The Human Fossil Record, Brain Endocasts: The Paleoneurological Evidence, Volume 3

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The Human Fossil Record

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The Human Fossil Record Series Editors Jeffrey H. Schwartz Department of Anthropology University of Pittsburgh Pittsburgh, Pennsylvania

Ian Tattersall Department of Anthropology American Museum of Natural History New York, New York

The Human Fossil Record, Volume One: Terminology and Craniodental Morphology of Genus Homo (Europe) by Jeffrey H. Schwartz, Ian Tattersall The Human Fossil Record, Volume Two: Craniodental Morphology of Genus Homo (Africa and Asia) by Jeffrey H. Schwartz, Ian Tattersall

Forthcoming Volume: The Human Fossil Record, Volume Four: Craniodental Morphology of Early Hominids by Jeffrey H. Schwartz, Ian Tattersall

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THE HUMAN FOSSIL RECORD Volume Three Brain Endocasts— The Paleoneurological Evidence

Ralph L. Holloway Department of Anthropology Columbia University New York, New York

Douglas C. Broadfield Department of Anthropology and Department of Biomedical Science Florida Atlantic University Boca Raton, Florida

Michael S. Yuan School of Dental and Oral Surgery Columbia University New York, New York

A John Wiley & Sons, Inc., Publication

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∞ This book is printed on acid-free paper.


c 2004 by John Wiley & Sons, Inc., Hoboken, New Jersey. All rights reserved. Copyright
Published simultaneously in Canada. No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, scanning or otherwise, except as permitted under Sections 107 or 108 of the 1976 United States Copyright Act, without either the prior written permission of the Publisher, or authorization through payment of the appropriate per-copy fee to the Copyright Clearance Center, 222 Rosewood Drive, Danvers, MA 01923, (978) 750-8400, fax (978) 750-4744. Requests to the Publisher for permission should be addressed to the Permissions Department, John Wiley & Sons, Inc., 111 River Street, Hoboken, NJ 07030, (201) 748-6011, fax (201) 748-6008, E-Mail: [email protected]. For ordering and customer service information please call 1-800-CALL-WILEY. Library of Congress Cataloging-in-Publication Data: The human fossil record. p. ; cm. Includes bibliographical references. Contents: v. 3. Brain Endocasts—The Paleoneurological Evidence/ Ralph L. Holloway, Douglas C. Broadfield, Michael S. Yuan ISBN 0-471-41823-4 (v. 3 : cloth : acid-free paper) 1. Fossil hominids. I. Holloway, Ralph L. II. Broadfield, Douglas C. III. Yuan, Michael S. GN282 .H83 2002 569.9—dc21

200102664

Printed in the United States of America. 10 9 8 7 6 5 4 3 2 1

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We dedicate this work to our families with love and thanks.

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Contents

PREFACE ACKNOWLEDGMENTS

xv xix

PART 1: Brain Evolution and Endocasts INTRODUCTION Lines of Evidence, DIRECT and INDIRECT

Endocranial Morphology and Terminology

17

Descriptive and Figure Format

23

PART 2: Methods and Materials of Endocast Analysis

3

Total Endocranial Brain Volume

29

5

Partial Brain Endocast Volumes

30

Brain Endocasts What Is a Brain Endocast? What Data Can Brain Endocasts Provide?

7 7

Endocast Volume Reliability

30

Brain Endocast Volumes by Formula

30

8

The Data Size Morphometric Data (See also Part 2: Methods and Materials of Endocast Analysis) Asymmetry Observations and Measurements Meningeal Patterns and Blood Supply (Arterial and Venous)

8 8

Asymmetry Observations and Measures Left-Right Petalias Asymmetries of the Broca’s Cap Region

Biobehavioral Significance of Brain Endocasts Absolute Brain Size Relative Brain Size The Reduction of Primary Visual Cortex and the Lunate Sulcus The Frontal and Prefrontal Lobes The Temporal Lobe

9 11

31 31 31

Regional Convolutional Details

33

Meningeal Patterns

33

Morphometric Analyses

35

PART 3: Endocasts of Early Hominids

11

BOURI 12 12 13 14 15 17

vii

41

BOU-VP-12/130

41

Gross Description

41

Volume and Method

41

Endocast Details

41

Morphometric Data

41

Significance

42

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CONTENTS

HADAR

44

AL 288-1 MORPH

44

Gross Description AL 162-28 AL 288-1 AL 333-45 AL 333-105 AL 444-2

44 44 44 44 44 44

Volume and Method AL 162-28 AL 288-1 AL 333-45 AL 333-105 AL 444-2

44 44 45 45 45 45

Endocast Details AL 162-28 AL 288-1 AL 333-45 AL 333-105 AL 444-2

45 45 45 45 46 46

Morphometric Data AL 162-28 AL 288-1 AL 333-45 AL 333-105 AL 444-2

46 46 46 46 47 47

Significance AL 162-28 AL 288-1 AL 333-45 AL 333-105 AL 444-2

47 47 47 47 47 48

KONSO

55

KGA-10-525

55

Gross Description

55

Volume and Method

55

Endocast Details

55

Morphometric Data

56

Significance

56

KOOBI FORA

58

KNM-ER 407 KNM-ER 732 KNM-ER 23000

58 58 58

Volume and Method KNM-ER 407 KNM-ER 732 KNM-ER 23000

58 58 58 59

Endocast Details KNM-ER 407 KNM-ER 732 KNM-ER 23000

59 59 59 59

Morphometric Data KNM-ER 407 KNM-ER 732 KNM-ER 23000

59 59 59 59

Significance KNM-ER 407 KNM-ER 732 KNM-ER 23000

59 59 60 60

MAKAPANSGAT

63

MLD 1 MORPH

63

Gross Description MLD 1 MLD 37/38

63 63 63

Volume and Method MLD 1 MLD 37/38

63 63 63

Endocast Details MLD 1 MLD 37/38

63 63 64

Morphometric Data MLD 1 MLD 37/38

64 64 64

Significance MLD 1 MLD 37/38

64 64 64

OLDUVAI

66

OH 5

66

Gross Description

66

Volume and Method

66

Endocast Details

66

KNM-ER 407 MORPH

58

Morphometric Data

67

Gross Description

58

Significance

67

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CONTENTS

OMO

69

OMO L338Y-6

69

Gross Description

69

Volume and Method

69

Endocast Details

69

Morphometric Data

69

Significance

70

STERKFONTEIN

72

STS 5 MORPH

72

Gross Description Sts 5 Sts 19/58 Sts 26 Sts 60 Sts 71 Stw 505 Type 2 Type 3

72 72 72 72 72 72 73 73 73

Volume and Method Sts 5 Sts 19/58 Sts 26 Sts 60 Sts 71 Stw 505 Type 2 Type 3

73 73 73 73 73 73 73 74 74

Endocast Details Sts 5 Sts 19/58 Sts 26 Sts 60 Sts 71 Stw 505 Type 2 Type 3

74 74 74 74 74 75 75 75 76

Morphometric Data Sts 5 Sts 19/58 Sts 26 Sts 60 Sts 71

76 76 76 76 76 76

Stw 505 Type 2 Type 3

77 77 77

Significance Sts 5 Sts 19/58 Sts 26 Sts 60 Sts 71 Stw 505 Type 2 Type 3

77 77 77 77 77 77 77 78 78

SWARTKRANS

90

SK 1585 MORPH

90

Gross Description SK 54 SK 859 SK 1585

90 90 90 90

Volume and Method SK 54 SK 859 SK 1585

90 90 90 91

Endocast Details SK 54 SK 859 SK 1585

91 91 91 91

Morphometric Data SK 54 SK 859 SK 1585

92 92 92 92

Significance SK 54 SK 859 SK 1585

92 92 92 92

TAUNG

96

TAUNG CHILD

96

Gross Description

96

Volume and Method

96

Endocast Details

97

Morphometric Data

98

Significance

98

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TURKANA (WEST TURKANA)

102

KNM-WT 17000 MORPH

102

Gross Description KNM-WT 13750 KNM-WT 17000 KNM-WT 17400

102 102 102 102

Volume and Method KNM-WT 13750 KNM-WT 17000 KNM-WT 17400

102 102 102 102

Endocast Details KNM-WT 13750 KNM-WT 17000 KNM-WT 17400

102 102 103 103

Morphometric Data KNM-WT 13750 KNM-WT 17000 KNM-WT 17400

103 103 103 103

Significance KNM-WT 13750 KNM-WT 17000 KNM-WT 17400

103 103 103 104

PART 4A: Africa BODO

111

Gross Description

111

Volume and Method

111

Endocast Details

111

Morphometric Data

111

Significance

111

JEBEL IRHOUD ( JEBEL IGHOUD)

114

Gross Description Jebel Irhoud 1 Jebel Irhoud 2

114 114 114

Volume and Method Jebel Irhoud 1 Jebel Irhoud 2

114 114 114

Endocast Details Jebel Irhoud 1 Jebel Irhoud 2

114 114 115

Morphometric Data

115

Jebel Irhoud 1 Jebel Irhoud 2

115 115

Significance Jebel Irhoud 1 Jebel Irhoud 2

115 115 115

KABWE

120

Gross Description

120

Volume and Method

120

Endocast Details

120

Morphometric Data

120

Significance

121

KOOBI FORA

123

KNM-ER 1470 MORPH

123

Gross Description Volume and Method

123 123

Endocast Details Morphometric Data Significance KNM-ER 1813 MORPH

123 124 124 124

Gross Description KNM-ER 1813 KNM-ER 1805

124 124 124

Volume and Method KNM-ER 1813 KNM-ER 1805

125 125 125

Endocast Details KNM-ER 1813 KNM-ER 1805

125 125 125

Morphometric Data KNM-ER 1813 KNM-ER 1805

125 125 126

Significance KNM-ER 1813 KNM-ER 1805

126 126 126

KNM-ER 992 MORPH

126

Gross Description KNM-ER 1590 KNM-ER 3732 KNM-ER 3733 KNM-ER 3883

126 126 126 127 127

Volume and Method KNM-ER 1590

127 127

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CONTENTS

KNM-ER 3732 KNM-ER 3733 KNM-ER 3883

127 127 127

Endocast Details KNM-ER 1590 KNM-ER 3732 KNM-ER 3733 KNM-ER 3883

127 127 127 127 128

Morphometric Data KNM-ER 1590 KNM-ER 3732 KNM-ER 3733 KNM-ER 3883

128 128 128 128 128

Significance KNM-ER 1590 KNM-ER 1470 KNM-ER 3732 KNM-ER 3733 KNM-ER 3883

129 129 129 129 129 129

NARIOKOTOME (WEST TURKANA)

139

KNM-WT 15000

139

Gross Description

139

Volume and Method

139

Endocast Details

139

Morphometric Data

139

Significance

140

OLDUVAI GORGE

143

OH 7 MORPH

143

Gross Description OH 7 OH 13 OH 16 OH 24

143 143 143 143 143

Volume and Method OH 7 OH 13 OH 16 OH 24

143 143 144 144 144

Endocast Details OH 7 OH 13 OH 16

144 144 144 145

OH 24

145

Morphometric Data OH 7 OH 13 OH 16 OH 24

145 145 146 146 146

Significance OH 7 OH 13 OH 16 OH 24

146 146 146 146 146

OH 9 MORPH

147

Gross Description OH 9 OH 12

147 147 147

Volume and Method OH 9 OH 12

147 147 147

Endocast Details OH 9 OH 12

147 147 147

Morphometric Data OH 9 OH 12

147 147 148

Significance OH 9 OH 12 SALE´

148 148 148 156

Gross Description

156

Volume and Method

156

Endocast Details

156

Morphometric Details

156

Significance

156

PART 4B: Asia, Eastern and Central NGANDONG (SOLO) Gross Description Ngandong 1 (Solo I) Ngandong 6 (Solo V) Ngandong 7 (Solo VI) Ngandong 13 (Solo X) Ngandong 14 (Solo XI)

163 163 163 163 163 163 163

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Volume and Method

163

Endocast Details Ngandong 1 Ngandong 6 Ngandong 7 Ngandong 13 Ngandong 14

163 163 164 164 164 164

Morphometric Data Ngandong 1 Ngandong 6 Ngandong 7 Ngandong 13 Ngandong 14

164 164 164 164 164 164

Significance

164

SAMBUNGMACAN

173

SAMBUNGMACAN 3 (SM 3)

173

Gross Description

173

Volume and Method

173

Endocast Details

173

Morphometric Data

173

Significance

174

SANGIRAN

176

Gross Description Sangiran 2 Sangiran 3 Sangiran 4 Sangiran 10 Sangiran 12 Sangiran 17

176 176 176 176 176 176 176

Volume and Method Sangiran 2 Sangiran 3 Sangiran 4 Sangiran 10 Sangiran 12 Sangiran 17

176 176 176 177 177 177 177

Endocast Details Sangiran 2 Sangiran 3 Sangiran 4 Sangiran 10 Sangiran 12 Sangiran 17

177 177 177 177 177 177 177

Morphometric Data Sangiran 2 Sangiran 3 Sangiran 4 Sangiran 10 Sangiran 12 Sangiran 17

178 178 178 178 178 178 178

Significance Sangiran 2 Sangiran 3 Sangiran 4 Sangiran 10 Sangiran 12 Sangiran 17 TRINIL

179 179 179 179 179 179 179 188

TRINIL 2

188

Gross Description

188

Volume and Method

188

Endocast Details

188

Morphometric Data

188

Significance

189

ZHOUKOUDIAN (CHOUKOUTIEN): LOWER CAVE

192

SKULL 111 LOCUS E

192

Gross Description Skull III, Locus E (Skull III, E) Skull I, Locus L (Skull I, L) Skull III, Locus L (Skull III, L)

192 192 192 192

Volume and Method Skull III, E Skull I, L Skull III, L

192 192 192 192

Endocast Details Skull III, E Skull I, L Skull III, L

193 193 193 193

Morphometric Data Skull III, E Skull I, L Skull III, L

193 193 193 194

Significance Skull III, E

194 194

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CONTENTS

Skull I, L Skull III, L

194 194

PART 4C: Asia, Western AMUD

225

Morphometric Data

225

Significance

225

KRAPINA 203

Gross Description

203

Volume and Method

203

Endocast Details

203

Morphometric Data

203

Significance

204

TESHIK-TASH

206

PART 4D: Europe ARAGO (TAUTAVEL)

211

Gross Description

211

Volume and Method

211

Endocast Details

211

Morphometric Data

211

Significance

211

BRNO

Endocast Details

215

BRNO II

215

BRNO III

215

COMBE CAPELLE

217

CRO-MAGNON

219

CRO-MAGNON III

219

DOLNI VESTONICE

221

229

Gross Description Krapina 3 (= Cranium C) Krapina 6 (= Cranium E)

229 229 229

Volume and Method Krapina 3 Krapina 6

229 229 229

Endocast Details Krapina 3 Krapina 6

230 230 230

Morphometric Data Krapina 3 Krapina 6

230 230 230

Significance Krapina 3 Krapina 6

230 230 230

LA CHAPELLE-AUX-SAINTS

234

Gross Description

234

Volume and Method

234

Endocast Details

234

Morphometric Data

234

Significance

235

LA FERRASSIE

238

LA FERRASSIE I

238

Gross Description

238

Volume and Method

238

222

Endocast Details

238

Gross Description

222

Morphometric Data

238

Volume and Method

222

Significance

239

Endocast Details

222

Morphometric Data

222

LA QUINA V

242

Significance

222

Gross Description

242

GIBRALTAR

225

Volume and Method

242

GIBRALTAR I

225

Endocast Details

242

Gross Description

225

Morphometric Data

242

Volume and Method

225

Significance

242

DOLNI VESTONICE III FELDHOFER GROTTO (NEANDERTHAL)

221

LA QUINA

242

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LAZARET

245

Gross Description

245

Volume and Method

245

Endocast Details

Spy 2

265

245

Significance Spy 1 Spy 2

265 265 265

Morphometric Data

245

SWANSCOMBE

268

Significance

245

Gross Description

268

LE MOUSTIER ´ LES COTTES

247

Volume and Method

268

249

Endocast Details

268

MONTE CIRCEO

250

Morphometric Data

268

Gross Description

250

Significance

268

Volume and Method

250

Endocast Details

250

Morphometric Data

251

Significance

251

PODKUMAK PREDMOSTI´

253 254

PREDMOSTI´ 3 PREDMOSTI´ 4

254

PREDMOSTI´ 9 PREDMOSTI´ 10

254

Significance

255

REILINGEN

261

254 254

PART 5: Endocranial Vasculature By Dominique Grimaud-Herv´e Illustrations by Pascal Herv´e ENDOCRANIAL VASCULATURE

273

Meningeal Patterns

273

Dural Venous Sinuses Sphenoparietal Sinus Petrosquamous Sinus Confluence of Sinuses (Confluens)

277 277 277 277

Significance of Endocranial Vasculature

277

PART 6: Hominid Endocasts: Some General Notes

Gross Description

261

Volume and Method

261

Mosaic Evolution

285

Endocast Details

261

Morphometric Data

261

Significance

262

Behavioral Dynamics Stage 1 Stage 2 Stage 3

288 289 290 290

Endocasts Yet to Be Studied

291

SPY

264

Gross Description Spy 1 Spy 2

264 264 264

Volume and Method Spy 1 Spy 2

264 264 264

Endocast Details Spy 1 Spy 2

264 264 264

Morphometric Data Spy 1

265 265

APPENDIX 1: ENDOCRANIAL VOLUMES OF THE FOSSIL HOMINIDS Notes for Appendix 1

295 296

APPENDIX 2: STATISTICAL ANALYSES OF ENDOCRANIAL VOLUMES BY TAXA

303

LITERATURE CITED

307

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Preface

volume of the hippocampus, or whether the amygdala was larger or smaller than expected. For the full story we would need many time machines equipped with video-cameras, PET, and MRI scan paraphenalia, dissection tools and microscopes, as well as the ability and tools necessary to collect DNA. Other scientists would take along the brains of extant primates for comparative analyses, despite the fact that such brains, whether of chimpanzees, Bonobos, gorillas, or orangutans, are not ancestral brains but rather those of extant species that have their own evolutionary lines of development. We prefer a more empirical approach, and that is what this volume is about. Brain endocasts—the casts made from the inside of the skull—are the only direct evidence we have about hominid brain evolution. The data resulting from analyzing such objects is admittedly limited in quantity and quality, but surely far from worthless. It deserves to be examined in the light of all we know from comparative neurology and modern functional neuroanatomy. This book is not a treatise regarding how the human brain evolved (indeed, we are purposely eschewing controversy over such speculations), but rather a detailed analysis of the direct evidence—the endocasts—and how these show changes through time, both in terms of brain size and what can be ascertained about the brain’s organization from surface features—for example, convolutional patterns, cerebral asymmetries, biometrical comparisons, and, thanks to the included contribution of Dr. Dominique Grimaud-Herv´e, meningeal patterns of the endocranial surface. What we are striving for herein is a scenario of hominid brain evolution based

The evolution of the human brain is surely a hot topic, if the number of articles and books written about the subject is any indication. Claims regarding single mutations, language genes, the relevance of microcephalic genes to encephalization; the role of protein in brain growth (and thus the necessity of hunting and scavenging early in hominid evolution); cooling of the brain, the expansion of the pelvis; selection for humor and good looks as a driving force of brain evolution; and the appearance of art as the only valid evidence for our human symbolic capacity are among the plethora of speculation recently put forward. And, this by no means exhausts the list. It is curious that in all of the scenarios described and for all the speculation provided (e.g., Crow, 2002) not a single source has bothered to examine the actual fossil evidence for human brain evolution, namely the paleoneurological record composed of the brain casts (endocasts) produced from the actual cranial remains of the fossil hominids from Australopithecus afarensis of three to four million years ago (MYA)—and potentially in earlier hominid species—through to modern Homo sapiens. Although there are a dozen or more brain endocasts of Neanderthals, none of these appear to have warranted examination beyond the amount of water the endocasts can displace or the amount of seeds that can fill their crania. Size clearly trumps all else in these scenarios. It is true that we will never fully understand how the human brain evolved. Brains do not fossilize, and even if they did, there is no way to read out their behavioral qualities. Still it is nice to know, for example, the

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on the direct fossil evidence, which consists of brain size, lobar patterns, shape and morphometric analyses, and asymmetries, as each of these variables has some correlation with behavioral variation. We do not mean to imply that we alone have made this attempt. We stand on the shoulders of others, namely Grafton Elliot Smith, W. E. LeGros Clark, Raoul and J. Anthony, Raymond Dart, G. H. Schepers, Ariens Kappers, Tilly Edinger, Marjorie LeMay, Veronika Kochekova, Harry Jerison, C. R. Connolly, Franz Weidenreich, Phillip V. Tobias, Len Radinsky, Dean Falk, and Wally Welker, and we are indebted to the crews of hominid searchers who have taken the political risks and suffered the hostile elements in their searches to provide the skeletal discoveries that have eventually led to the production of the brain endocasts that we study. This volume is certainly not free of speculation, but we have tried to frame our speculations on the basis of an amalgam of current neuroscience and the fossil record. We have not discovered any genes for language, asymmetries, or reduction of Brodmann’s area 17; nor do we know what the distribution of oxytocin receptors were like in the thalamus of Homo habilis. We do not know what drove or produced sexual dimorphism in brain size, and we cannot detect sexually dimorphic neural nuclei or fiber tracts in our paleoneurological record. Indeed, we can only guess as to the sexual identities of most of our fossil cranial remains. We have not discovered or uncovered any modules in the hominid brain that we can plug into the EEA. In time, with the future unraveling of DNA and the stereochemical properties of the proteins they help produce, we might have a better picture of the molecular changes that underlie our more gross neuroanatomical variation. Instead, what we find presently in our paleoneurological remains are the variates of size, overall morphology, asymmetries, regional differences in gyri and sulci, and variations in meningeal patterns. We use these to offer speculations about their interrelatedness and evolution through time, and even here we often feel on shaky ground. Finally, we have not studied these paleoneurological remains to advance any particular taxonomic viewpoint. We do not regard the generic and specific names used for fossil hominids as necessarily writ in stone, and we are not (nor do we wish to be) involved in taxonomic controversies. Indeed, the authors individually disagree on the taxonomic affinities of many of the specimens presented in this volume. To that end, it is worth noting, outside the general text, the taxonomy that we generally adhere to in this volume. We use a conservative (in the

sense of mostly consensual) classification where we recognize the species afarensis, africanus, garhi, aethiopicus, robustus, and boisei of the genus Australopithecus (earlier species do exist, but we have no endocranial remains of them as yet). The last thing we wish to become involved in are “splitter-lumper” controversies. If we use the term Zinjanthropus or Paranthropus, it is in the hope of distinguishing them from other morphs. We believe that mini-adaptive radiations were probable in the earliest phases of hominid evolution. In addition we believe that adaptive radiations were less frequent within the genus Homo, and we believe that the species habilis, erectus, rudolfensis, and sapiens were true species. We regard H. ergaster, H. heidelbergensis, and H. antecessor as most probably subspecific or “racial” variants of Homo erectus, and we regard H. neanderthalensis as a within-species variant of Homo sapiens. We trust that the series Editors will forgive us. With more fossil materials and more study, it is certainly possible that what we call early H. habilis, as represented by OH 7, OH 13, OH 16, OH 24, and OH 62, will turn out to be simply more advanced australopithecines. Indeed, as this Preface is being written, a newly announced discovery from Olduvai Gorge (Blumenshine et al., 2003) suggests that OH 7 and the new OH 65 are the same taxon, thus bringing into question the sanctity of Homo rudolfensis as a taxon. The recent designation of the Dmanisi Georgian finds as Homo georgicus seems precipitous to us, but we have not seen the fossils nor had access to their endocranial remains. We can state the same for the Atapuerca materials in Spain, known as Homo antecessor. We note that White and his colleagues have labeled the Middle Awash hominids of 160 K years ago as Homo sapiens idaltu, the latter word meaning “elder,” thus suggesting that it was the earliest member Homo sapiens but quite possibly of a different subspecies than our own Homo sapiens sapiens (White et al., 2003). We find this wholly acceptable. In sum, if we err it is on the side of restricting both genera and species labels to very distinct morphologies, and accepting subspecific labels for what appear to have been either breeding isolates or populations with some degree of chronological and morphological identity. Whatever the “true” taxonomic relationships of all the hominids, we regard each of the endocasts we have studied as representing once living, breathing, pulsating human or near-human individuals with cognitive capacities and emotions very similar, albeit not identical, to our own. The skeletal and endocranial remains didn’t come out of the deposits waving labels, and it is up to us, the social

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constructors, to place them into some taxonomic scheme so that we know whom we are talking about. Naming different species, however, implies genealogical distances that we cannot test by their reproductive abilities, and we remain uncertain that our knowledge of the genetic basis of morphological variations warrants assumptions of reproductive isolation in the modern sense of biological species (e.g., Mayr, 1963). While we appreciate that others (e.g., Tattersall, 1999; Schwartz and Tattersall, 2000) prefer to use a morphological species concept, we are skeptical that such discrimination can be applied to indicate a true biological species. We are certain that the morphological differences of endocasts

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we detail herein are of little value in making taxonomic distinctions, given the wide range of variability seen in size, asymmetries, shape, and morphology of brain endocasts for our own species. If these are sins, please forgive us. We present this material largely in alphabetical order so that we can follow the rationale and organization of the previous two volumes of the series. We are grateful that the editors have allowed us to present the australopithecine materials in a separate, but alphabetically arranged, section. The genus Homo is presented alphabetically within broad geographical regions, namely Africa, Europe, and Asia.

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Acknowledgments

I benefited greatly from the largesse of Professor Raymond Dart, who sent me all of his reprints when I was in graduate school. I also greatly benefited from the kindness of Professor Phillip Tobias, who invited me to come to the University of Witwatersrand to study the brain endocasts of the South African australopithecines, a kindness that propelled me into this career in 1969. Alun Hughes was a splendid technician and support for my endeavors in South Africa, and I remember him with great fondness, as well as the kindness of Roddy Klomfass and others at Wits, and the hospitality of Dr. Bob Brain, then director of the Transvaal Museum, in Pretoria. My own dissertation, completed in 1964, had concluded that brain endocasts were essentially useless, and my hopeful career as a quantitative primate neurohistologist was met with a certain lack of enthusiasm by Columbia’s neuroscience elite, who felt that if one couldn’t know what was happening in the brains of Aplysia, the sea-slug, what hope was there for learning about primate brains . . . a skepticism that I hope I have dispelled through the years. It is to Professor Phillip Tobias that I am most indebted for his gracious permission to study those precious objects in the Department of Anatomy at the University of Witwatersrand, and it was he who also gave me permission to describe the SK 1585 brain endocast from Swartkrans, with Dr. Bob Brain’s encouragement. It was, I believe, Phillip Tobias also who alerted Louis Leakey that I could be trusted in the lab, and thus I had additional opportunities through the kindness of Louis, Mary, and Richard Leakey to undertake study of their spectacular finds. My friend and colleague,

Our thanks must first go to Drs. Jeffrey Schwartz, University of Pittsburgh, and Ian Tattersall, AMNH, for their invitation to us to write this volume. We hope that the availability of clear descriptions, measurements, and illustrations of these hominid brain endocasts, which reflect the only direct evidence available for human brain evolution, will encourage others to enter into serious studies of them and the data they provide. For too long these studies have been conducted by only a few scientists, and these objects deserve better. It is unfortunately a simple fact that those who have studied brain endocasts of primates, and humans, in particular, can be squeezed into a single London telephone booth, albeit with considerable protest. Ralph L. Holloway, Dean Falk, Phillip V. Tobias, Harry Jerison, Dominique Grimaud-Herv´e, Anne Weaver, Doug Broadfield and Michael Yuan, are the current crop, so to speak, and we stand on the foundations others have fashioned. Colleagues who have passed away, or who have retired from their disciplines, such as Len Radinsky, Tilly Edinger, Wally Welker, Roger Saban, Raoul and Jean Anthony, James McGregor, Franz Weidenreich, Davidson Black, Veronika Kotchekova, Raymond Dart, Grafton Elliot Smith, Sir W. E. LeGros Clark, George Schepers, and C. J. Connolly, would have made a fabulous international conference to which we “youngsters” would have prayed for an invitation. Perhaps the future will see such a conference come to pass.

From Ralph L. Holloway We each must speak to the development of our own individual careers. As the senior author of this volume

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Dr. Alan Walker, was always a tremendous help to me in these endeavors, and I am most grateful for the casts he has provided to me of some of the earlier australopithecines that are included in this volume. During 1971 and 1972, I spent most of my time in Kenya and S. Africa, with a short trip to Indonesia to work with my esteemed colleague Teuku Jacob on the newer Homo erectus materials. I also had the honor of working with Dr. Ralph von Koenigswald of the Senckenberg Museum in Frankfurt on the Solo crania and with Dr. A. Legu`ebe of the Brussels Museum on the Spy I and II endocasts. In the late 1970s, I was allowed to visit the exciting collections of the newly discovered A. afarensis materials under Dr. Donald Johanson’s curatorship at the Cleveland Museum of Natural History, where I had the privilege and pleasure of working with Drs. Tim White, William Kimbel, Bruce Latimer, and Owen Lovejoy. Their friendship and faith in my work have also been of the utmost importance to this project. Their students, including Drs. Gen Suwa, Berhane Asfaw, and David DeGusta, later provided me with excellent and challenging brain endocast materials for study and description, some appearing herein for the first time. Drs. Clark Howell, Yoel Rak, and Yves Coppens were instrumental in giving me the opportunity to describe the Omo 338y-6 specimen, which has become so controversial recently, and I am deeply indebted to them. I am also indebted to Dr. Henri de Lumley for allowing me to participate in the description of the Arago frontal and parietal endocast portions from his collection. Dr. Roger Saban was most kind to me during one of my trips to Paris, as were Dr. Yves Coppens, and Franc¸ois and C´ecile Poplin, and I thank them for their friendship and hospitality. Dr. Dominique Grimaud-Herv´e, in addition to kindly contributing to this volume, has been a true friend and colleague from whose help and encouragement I have greatly benefited. We are very grateful to her husband, Dr. Pascal Herv´e, for his excellent drawings of the meningeal vessels that appear in this volume. I similarly wish to thank Drs. Luca Bondioli and Roberto Machiarelli, Museo Pigorini, Rome, Italy, for the beautiful endocast of the Monte Circeo Neanderthal, which we include in this volume. In England, it was Dr. Theya Molleson to whom I am most grateful for shepherding me through the intricacies of the British Museum of Natural History, and arranging our studies on the endocast collections, and Gorilla crania. I owe my sincerest thanks to Drs. Robert D. Martin and Michael Day for their friendship and

encouragement and to Robert Parsons for a splendid silicone rubber endocast of the Rhodesian (Kabwe) skull, which forms the basis for a new description in this volume. Here on the home front, numerous colleagues particularly stand out as providing the best of collegiality, friendship, and hospitality. Drs. Alan Mann and Janet Monge of the University of Pennsylvania and Bryn Mawr (Alan is now at Princeton University) have been the truest of friends, always encouraging and helpful with their time and materials. Were it not for their expertise in casting fossil hominids, some of these descriptions would be much the poorer. Drs. Carole MacLeod, Jim Rilling, Dan Buxhoeveden, and Anne Weaver have been wonderful supportive colleagues. I am also very grateful to Drs. Nick Toth and Kathy Schick of the University of Indiana, for their encouragement and friendship, and to Dr. Milford Wolpoff, University of Michigan, for his help with the Krapina crania, and his encouragement. To Drs. Ken Mowbray, Sam Marquez, and Mr. Gary Sawyer, John Gurche, Dr. Emanuel Gilissen, I add a special note of thanks for the wonderful workmanship, friendship, and good times that accompanied the quest for studying our brain’s evolutionary pathway. I also wish to thank Dr. Jill Shapiro, Dr. Chet Sherwood, and Francys Subiaul of Columbia University for the pleasure of working together on several aspects of brain endocast morphology. Chet Sherwood has been particularly helpful in reading some of the earlier versions of this work and has made several useful suggestions. In addition, our thanks go to Dr. Chris Ruff and Dr. Erik Trinkaus for their help with several endocranial volumes, and for allowing us to incorporate them in Appendix 1. I wish to thank Marilyn Astwood, Juana Cabrera, and other staff in the Department of Anthropology, who have been so helpful during my years at Columbia, and who have helped in the task of assuaging the growing isolation of Physical Anthropology in the Department of Anthropology and at Columbia University. Thank goodness for the many interested students in such times, most particularly the undergraduates who are so eager to learn about their evolutionary past despite the lack of encouragement from the remaining faculty. To Dr. Graham Kavanagh, Carole Travis, and Chuck MacAlexander, I owe special thanks for helping me to keep to the straight and narrow, and for their genuine interest and continual encouragement. Last each of us thanks our families for enduring our moods and labors. I am especially grateful to my wife, Dr. Daisy H.

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Dwyer, who has been uncomplainingly enduring and without whose encouragement and editorial expertise this volume would not have been completed. My children, Marguerite, Eric, and Ben, each provided me the neuro-ontogenetic lessons that nothing is writ in genetic or environmental stone, and left me the freedom and latitude to complete this project. Finally this voyage has occasioned many stops in numerous countries throughout Asia, Africa, and Europe over the past 34 years, and I have benefited from the kindness, courtesy, and hospitality of many people. I may well have forgotten names, but not how well I was treated. Doug Broadfield and Michael Yuan also wish to thank our senior author, Ralph Holloway, for the dedicated friendship and guidance he has given us and his students over his career. The cumulative sixty-plus years of experience described in this volume is the result of Ralph’s willingness to discuss, describe, and display his

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knowledge of human brain evolution and endocasts with anyone interested. We are grateful for Ralph’s willingness to entrust us with the future of this field we have merely begun to explore. All of the authors also wish to thank our collective colleagues for their helpful comments and support, Mr. Don Broadfield, Dr. Chet Sherwood, Dr. Jill Shapiro, Dr. Mindy Liu, and, in particular, the faculty of the New York Consortium of Evolutionary Primatology, especially Drs. Jeffrey T. Laitman, Eric Delson, and Ian Tattersall. In addition to those mentioned previously, we also thank Dr. Robert D. Martin for his comments on allometry and Jeffrey Schwartz for his assistance in bringing this volume together. Last, we wish to thank our own students, the next generation of researchers in brain evolution, for their assistance in the preparation and helpful comments of this volume: Francys Subiaul, Tania Ellis, Stacie Freeland, Kristina Harper, Julie Cribb, Alice Stader, and Andrew Halloran.

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P A R T

O N E

Brain Evolution and Endocasts

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Introduction

The brain is the central organ responsible for making humans both dramatically different from and yet very similar to our closest relatives, particularly the chimpanzee and the gorilla. The differences are mostly behavioral, involving the ability to learn and generate symbols, to manipulate symbol systems, to communicate with these systems (i.e., true language), to develop very high levels of intelligence, and to develop a large variety of skills, including artistic expression and perhaps other cognitive domains just beginning to be explored. Thanks to this organ and successive generations of humanly accumulated “culture,” the human animal holds the fate of the species, indeed all of the earth’s species, in its purview. We are the most dangerous animal going and a genus with a very short paleontological record. It remains to be seen how we use this brain that we have evolved over the past few million years. The human brain is absolutely the largest among primates, and while its relative brain weight is not the highest, the combination of both large absolute and relative size is testimony to the importance of this organ in human evolution. There is also evidence, beyond size considerations, that the human brain is uniquely organized. However, no new structures, either in terms of brain nuclei or fiber, tracts are evident in our own species. Differences in the quantitative relationships between brain nuclei and fiber tracts among different pri-

mate species are referred to as “reorganization” (as first expressed by Smith, 1924, and Dart, 1925, and particularly his 1956 paper; see also Holloway, 1964, 1966, 1967, 1968, 1969, 1979, 1981, 1983, 1995, 1996, 2002; Holloway et al., 2003). These differences suggest that species-specific patterns of behavior have a neural basis, however difficult it is to specify exactly the causal links between neural structure and behavior. Preuss’ (2000, 2001; Preuss et al., 1999) findings regarding different connectivity in certain layers of primary visual striate cortex in Homo sapiens, as in Brodmann’s area 17 (see Fig. 1 for Brodmann’s cytoarchitectural maps, and Table 1 for functional roles of these areas), demonstrates species-specific differences without concomitant volumetric differences in neural nuclei or cortical areas, as does the demonstration of different cortical columns by Buxhoeveden and Casanova (2002). The work on oxytocin receptors in the brains of prairie and mountain voles by Insel and Shapiro (1991) also underlines for us the importance of reorganization at yet another neural level, that of neuroreceptor sites (see Fig. 2 for examples of reorganizational changes possible without volumetric differences in total brain size). In addition the human brain shows different degrees of cerebral asymmetries than known for pongid brains (Holloway and de Lacoste, 1982). Indeed, our difficulty in accepting Jerison’s (1973, 2002) view regarding the triviality of the reorganization concept for humans has recently been reinforced by Finlay et al. (2001; see also Holloway, 1974, 1979, 2002, for critique) who showed that there is a large neurogenetic (thus developmental) constraint operating in most of the animal kingdom,

The Human Fossil Record, Volume 3, by Ralph L. Holloway, Douglas C. Broadfield, and Michael S. Yuan. C 2004 John Wiley & Sons, Inc. ISBN 0-471-41823-4 Copyright


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Figure 1. Brodmann’s (1909) cytoarchitectural maps of the human brain. A: Lateral view; B: Medial view.

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TABLE 1 Major cortical regions in early hominid evolution Cortical Regions Primary visual striate cortex Posterior parietal and anterior occipital (peri- and parastriate cortex) Posterior parietal, superior lobule Posterior parietal, inferior lobule (mostly right side; left side processes symbolic-analytical) Posterior parietal, inferior lobule (mostly right side; holistic, gestalt processing) Posterior superior temporal cortex

Brodmann’s Areas 17 18, 19

Lateral prefrontal cortex

Primary visual Secondary and tertiary visual integration with area 17 Secondary somatosensory Angular gyrus; perception of spatial relations among objects; face recognition Supramarginal gyrus, spatial ability

5, 7 39 40 22

Posterior inferior temporal

37 44, 45, 47 (also 8, 9, 10, 13, 46)

and in particular, mammals, although they downplayed the very real differences in species-specific behavior patterns that are underlain by small or sometimes large reorganizational shifts in neural nuclei and fiber tracts. Progress in both field and laboratory studies of chimpanzees, and studies using noninvasive imaging techniques, such as PET, may eventually provide us with a better understanding of how neural structures and processes underlay observable and testable behavioral patterns. In the meantime comparative and paleontological records provide the best available data regarding how the human species evolved from essentially bipedal, small-brained, small-bodied apes some 5 to 7 million years ago (MYA).

Lines of Evidence, DIRECT and INDIRECT This volume is devoted almost exclusively to one line of evidence regarding human brain evolution, namely paleoneurology. While we also rely on the comparative neurological data that exist for modern primates, such as data regarding their brain and body weights, neural nuclear sizes, and cytoarchitectonic patterns in the cerebral cortex and other structures, only brain size is readily available from the human fossil record (aside from some controversial interpretations of cortical sulcal patterns and cerebral asymmetries), and these data are provided by brain endocasts. As noted (Holloway, 1966, 1968, 1975, 1979, 1983, 1996), we consistently regard the comparative neurological data as indirect because it is

Functions

Wernicke’s area, posterior superior temporal gyrus; comprehension of language. Polymodal integration, visual, auditory; perception and memory of objects’ qualities. Broca’s area (Broca’s cap), motor control of vocalization, language Complex cognitive functioning, memory, inhibiton of impulse, foresight, etc

data for extant species, not ancestral forms. The brain endocasts of our fossil ancestors are the only direct evidence from paleontology. It is important to understand that the indirect evidence from extant brains is as rich and as varied as our techniques do or will allow, and that this evidence is indispensable in enlarging our understanding of the relationships between neural and behavioral variation in different living animals, as studied both under natural and laboratory conditions. We particularly recommend the excellent paper by Geary and Huffman (2002), which discusses these issues completely. How the evidence from comparative neuroanatomy is used to infer the evolutionary dynamics in our species’ brain is, however, often dependent on what is being viewed in evolutionary terms. For example, the concept of reorganization in human brain evolution might be a trivial concern if one is examining broad genetic and evolutionary conservatism between large numbers of taxa as do Finlay et al. (2001) and Jerison (1973) before them. Indeed, if one is trying to explain species-specific differences in behavior, for Homo sapiens or even for all animal species, the constraints become trivial while the reorganizational events rise in importance (Holloway, 1974, 1979, 2001). We expect the principle of uniformitarianism to operate, allowing us to move from the extant indirect evidence to speculations about the direct evidence manifested in the brain endocasts of the fossil record. It is no secret, of course, that the direct evidence is very limited, since brains do not fossilize, thus rendering forever

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Figure 2. Possible scenarios of brain changes through time (T1 to T2). A: The brain, shown with two hemispheres (left and right), and two transverse dotted lines that represent the central and lunate sulci, respectively. The change from T1 to T2 is simply an increase in size (absolute) without any change between the size of components or connections between them. This change could occur isometrically or allometrically. B: The change from T1 to T2 does not involve any change in absolute brain size, but rather a change in components, such that the lunate sulcus is placed more posteriorly, thus expanding the posterior portion of parietal association cortex. This is a reorganizational model. C: Changes in hierarchical development without any change in absolute brain size from T1 to T2. The arrows represent fiber systems maturing at different rates and/or increasing in number between different cortical regions through the corpus callosum, although other brain structures and fiber systems could be involved. D: Absolute brain size remains the same from T1 to T2, but a more human-type of hemispheric asymmetrical petalial pattern emerges (i.e., left occipital, right frontal). E: Absolute brain size remains the same from T1 to T2, but there is a redistribution of neuroreceptors.

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INTRODUCTION

mute (but we hope not also moot) the actual neural organization that existed in the past. When considering the interplay between direct and indirect lines of evidence, two important facts should be kept in mind. First, hominid and pongid lines have been separated in their evolutionary development for some 5 to 7 million years, and second, we have no brain endocasts representing fossil pongid evolution from the split of 5 to 7 million years ago to the present, as evidenced by extant species of chimpanzee or gorilla. Therefore one should always view with a modicum of skepticism the tendency to rely on observations from extant primate neuroanatomy and behavior, the latter from both field and laboratory studies, when we extrapolate from these studies to the evolutionary development of our own species.

Brain Endocasts What Is a Brain Endocast? A brain endocast is nothing more than a cast that is made of the interior of the neurocranium of a skull, which is that part of the cranium that houses the brain. From here on, we refer to these as simply endocasts, the term “brain endocast” actually being redundant. Endocasts may be natural or human-made. We speak of a natural endocast as one that results when, after death, the cranium is infiltrated with fine sediments through the cranial foramina, including the foramen magnum. In time these sediments filling the cranium, or some part of it, become indurated with calcareous water secretions that eventuate in a rock-like cast inside the cranium. This process probably takes hundreds if not thousands of years, although no one really knows how long it takes to make a natural endocast. The famous Taung, Sts 60, SK 1585, types II and III, from South Africa are wellknown examples of natural endocasts. Some endocasts have an almost gem-like quality to them, and indeed, the medial side of Taung is replete with calcite crystals. Human-made endocasts (e.g., all of the genus Homo from Asia, Africa, and Europe) are casts made by applying a molding material, such as liquid latex rubber or silicon rubber to the inside of the cranium or a portion thereof. After the application of the requisite number of coats and the drying of the molding material, the cast is peeled away from the cranial fragment(s) and is ready for reconstruction, examination, measurement, description, and so on. Often the human-made endocast is only partially complete. Cast from incomplete cranial fragments, it is reconstructed by adding modeling clay

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or plasticene to the missing sections to best effect an accurate approximation of the overall size and shape of the original brain. Endocasts can also be made from either hemisected or whole crania. Many endocasts in other collections, such as at University of the Witwatersrand, have been made simply by pouring plaster-of-Paris into cranial portions. Endocasts are also made from extant animal species, and animal endocasts have become important components of the comparative collection. At Columbia University alone we have a collection of some 40 Gorilla gorilla, 36 Pan troglodytes, and 44 Pan paniscus whole brain endocasts, just to mention the African apes, with dozens more of Pongo and Hylobates. These endocasts were made from specimens borrowed from various museums and institutions. Historically the study of brain casts is relatively old. Tilly Edinger (1949), in her historical paper, mentions Oken’s observation in 1819 of some petrified mud in a pterodactyl skull, and similarly references that of a crocodilian by Owen in 1841. By 1929, Tilly Edinger had counted some 280 papers devoted to such studies, with another 137 in her survey of 1937. Edinger championed paleoneurology as an important corrective to comparative neuroanatomy that had, and still has, a tendency to regard living extant brains as evidence of evolutionary lines of descent, a tendency that has been particularly common in much of psychology and comparative neuroscience, as well as anthropology. Edinger’s (1949) study of the evolution of the horse brain, a classic text that integrated data on size and organizational changes throughout the Tertiary, is still worthy of citation: On the other hand, paleontology can . . . reject the continuation of the quoted sentence, “until in man, we have the great development of the frontal areas . . .” The brain of Homo sapiens has not evolved from the brains it is compared with by comparative anatomy; it developed within the Hominidae, a late stage in the evolution of this family whose other species are all extinct.

Another valuable historical treatise on endocasts is “Paleoneurology,” written by Veronica Kochetkova (1978) with important editing by Harry and Irene Jerison. This book deals almost exclusively with the paleoneurology of hominids and quantitative arc-chord measures of their endocasts, various methods used to calculate endocranial volumes from linear measurements, and also provides a valuable historical overview of primate paleoneurology. Nonhuman primate paleoneurology was best covered by the numerous writings

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Figure 3. Tissue layers of the skull and brain. of the late Len Radinsky (e.g., 1972, 1975, and 1979) whose premature death robbed paleoneurology, primatology, and anthropology of an extremely skilled worker and valued colleague. Additional sources that examine the history of paleoneurology can be found in Hirschler (1942), Connolly (1950), Gurche (1978), and Falk (1992).

What Data Can Brain Endocasts Provide? Before we discuss the data available from endocasts, whether natural or human-made, it is necessary to explain exactly what is being cast. An endocast is not a cast of the brain; it is a cast made of the internal table of cranial bone. In life, three layers of tissue surround the brain (Fig. 3). (1) Immediately investing the brain is the pia mater that enfolds the brain and penetrates into the sulci of the brain. (2) Surrounding the pia mater is the arachnoid tissue, a fibrous layer that holds the cerebrospinal fluid (CSF), which acts partially as a shock-absorbing device to the surface of the brain against external insults. (3) Surrounding the arachnoid tissue is the dense, thicker and tough dura mater, whose outer layer adheres to the internal table of cranial bone. It is these three layers that naturally “conspire” against

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the living brain making a totally faithful impression of all its gyri and sulci against the internal table of cranial bone (e.g., see Symington, 1916; Clark et al., 1936; Clark, 1947; Hirschler, 1942; Tobias, 1991). Some gyri and sulci can, and do, imprint themselves through these tissues and leave traces on the internal table of bone, but this is a highly variable, and at present, an unexplained phenomenon (e.g., see Welker, 1990; Tobias, 1991; Connolly, 1950). As we will see, the endocasts of the Pliocene gracile morphs from South Africa show rather more convolutional detail than do Homo endocasts. Among the African apes, Gorilla endocasts show almost no convolutional details in comparison to endocasts of Pan troglodytes. In general, primary sulci such as the Sylvian or lateral fissure are present in endocasts, but fine secondary and tertiary convolutions of the frontal, parietal, and temporal association cortex are seldom visible. The Rolandic or central sulcus, though, is never present on hominoid endocasts, most likely because the arachnoid tissue and CSF form a cistern (accumulation) in that region. However, it is inaccurate to say that no gyri or sulci imprint upon the internal table of cranial bone; rather, the process is variable. Indeed, as we will see throughout the following descriptions, some important sulcal details are occasionally available from endocasts.

The Data Size Endocasts provide an estimate of cranial volume. We usually refer to cranial volume as cranial capacity, and this in turn provides an estimate of actual brain weight. Brain weight and cranial capacity are not, of course, identical, but are often regarded as practically synonymous, cranial capacity being on the order of roughly 10% greater than brain weight. Cranial capacity is greater because it includes the meninges, CSF, and cranial nerves. Anne Weaver (pers. comm.) has developed an algorithm for calculating brain weights from cranial capacity, which is: Brain volume (in cc) = 18.575 + 0.7689 × Cranial capacity This formula is based on a sample of 12 human brains, and provided an R2 -squared of 0.99. The cranial capacity of a brain endocast is usually measured by the technique of water displacement. The displaced water can be either measured

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INTRODUCTION

volumetrically (i.e., with a graduated cylinder), or, thanks to Archimedes’ principle, can be weighed directly. (This author has always found the weighing of displaced water more consistent and accurate.) On comparative endocast collections that are from complete crania, the volume of water displaced is weighed directly to the nearest gram. The endocasts in our collection at Columbia University were made using liquid rubber latex (Admold 3820). The layers were vulcanized by heat, and this shell was removed from the inside of the cranium. The endocast was floated in water as the shell was filled with liquid plaster of paris to equalize hydrostatic pressures and provide stability to the endocast shell. The whole is allowed to harden while immersed in water (Holloway, 1970a, 1973, 1975, 1978a, b). The accuracy of size determinations from endocasts depends on at least two key factors: (1) completeness of the endocast and added reconstructed portions, and (2) lack or presence of distortion of the endocast. Completeness of the Endocast. The endocast of Sts 5, Mrs. (or Ms.) Ples, is a complete endocast providing an endocranial volume of 485 ml, while that of the Taung specimen lacks a portion of the prefrontal region of the endocast, which must be added, and includes matrix that must be removed prior to measuring. The Taung specimen yielded an endocranial capacity of 404 ml, which is considerably lower than the 525 ml originally reported by Dart in 1925 (Holloway, 1970b). This represents not an adult volume, but a child’s value, which is calculated to be 440 ml on the basis of the dentition. When the greater the part of the endocranium is missing, the reconstruction is less reliable. The reconstruction returns the missing volumetric portions by following the shape outline of what is present by replicating the most probable missing brain portions. In earlier papers (e.g., Holloway, 1973, 1975), it was indicated that each endocast requires its own methodology. For example, Method A refers to “direct water displacement of either a full or hemi-endocast with minimal plasticene reconstruction” (Holloway, 1973: 450), such as with Taung, STS60, STS5, and SK1585. Method B refers to “an ascertainment based on the partial endocast method as described by Tobias (1967, 1971)” such as with STS19/58, MLD 1, or OH7, where undistorted portions of an endocast are compared to the whole endocast as a proportion. Method C “uses extensive plasticene reconstruction involving close to

half of the total endocast” and Method D refers to the formula V = f [0.5(LWB + LWH )] described by Mackinnon et al. (1956). Here f is determined from other complete endocasts of the same taxon, or closely related endocasts (Holloway, 1973: 450), L is endocast length from frontal pole to occipital pole, W is maximal width or breadth of the endocast usually taken at the superior temporal level, B is the length from bregma to basion, and H is the distance from vertex to deepest portion of the cerebellar lobes. Examples of Method C would be OH 13, OH12, and Krapina 3, while Method D would include endocasts such MLD37/38 and KNM-ER 406. Kochetkova (1978) provides several additional equations that some workers have used in the past. In addition Holloway (1973, 1975) suggests a four-point scale to use in a subjective evaluation of confidence in the accuracy of determination, depending on the overall completeness of the original, amount of distortion, and so on, with 1 being the highest in confidence. On this basis the Taung 404 ml volume would be scored a 1 and MLD37/38 a 3 or 4. Lack or Presence of Distortion of the Endocast. A partial and deformed demi-cranial example is that of Sts 71. At the right side there was plastic deformation of the occipital region and a medially depressed collapse of the temporal lobe (Holloway, 1970a, 1972, 1999). When it was first measured, after correcting for postmortem distortion, Holloway (1972) reported a volume of 428 ml. More recently Falk (1998) and Conroy et al. (1998) suggested a drastically lower volume of 375 ml, apparently unaware of the distortion. Shortly after Conroy et al. (2000) validated the earlier Holloway (1972) determination by taking distortion into account. As we will learn in the chapter on australopithecines (e.g., AL 444, Stw 505, OH 24, and the Bodo specimen), distortion can significantly affect volume determinations.

Morphometric Data (See also Part 2: Methods and Materials of Endocast Analysis) Endocasts not only manifest overall size; they also manifest shape, which can yield both absolute measurements (chords and arcs between landmarks) and indexes or ratios between measurements. Commonly measured are cerebral length (measured from the frontal to occipital poles), maximum breadth or width, cerebral height

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Figure 4. Demonstration of the location of the lunate sulcus (LS) in Stw 505 (A), and Pan troglodytes (B) (scale = 1 cm). (vertex to the deepest portion of the temporal lobe), and width of the cerebellar lobes. Other measurements are included depending on the degree of completeness of the endocast. Sometimes it is possible to measure distances between particular sulcal landmarks and to compare these and their attending indexes with those found on actual brains, for example, as between the chimpanzee brain and the Stw 505 endocast, to ascertain the relative position of the lunate sulcus, which delimits the anterior extent of the primary visual striate cortex (PVC), or area 17 of Brodmann (Fig. 4). Connolly (1950), Kochetkova (1978), and Grimaud-Herv´e (1997) offer numerous linear and arc measurements and indexes in their descriptions of endocasts and brains. Another morphological approach has been to stereoplot radial distances from the endocast surface to a homologous central reference plane (e.g., going through the frontal and occipital poles), using a variety of multivariate statistical techniques, to compare surface shapes between taxa once size has been corrected for (e.g., Holloway, 1978b). This technique has revealed that the shape of the transitional region between Brodmann’s area 17 and posterior association cortex showed the most shape change. More recently

MacLeod et al. (2002) have used computer-imaging techniques to do the same thing (i.e., depict shape changes on brain endocast surfaces of particular fossil hominids from an average configuration). The degree of differences can then be color-coded, showing “hot” and “cold” spots or regions. Unfortunately, this method misses important neurological reorganizational changes that are not always reflected as shape changes, such as the reduction of Brodmann’s area 17, PVC. In addition observations on the shape of particular regions can be made as, for example, regarding the roundedness or lack thereof of the prefrontal lobes, or whether the third inferior frontal convolution, which includes Broca’s area, has a more human or pongidlike appearance. Do the cerebral hemispheres overhang the cerebellar lobes? These characteristics, and many other considerations, require an appreciation of what brain endocast shapes provide, and can lead to useful hypotheses, based on actual measurements. In general, the divisions between the various cerebral lobes (frontal, parietal, temporal, occipital) are not actually visible on brain endocasts, given the distribution of CSF and meninges, so quantitative estimates of cerebral surface areas are at best only approximations.

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Asymmetry Observations and Measurements As is well known, the cerebral hemispheres are rarely perfectly symmetrical, and depending on the degree of preservation of cerebral portions from the left and right sides and the lack of distortion, one can observe whether or not there are petalial patterns, which suggest the possibility of hemispheric specializations such as handedness and language capabilities (LeMay et al., 1976). Petalias are simply extensions of the cerebral cortex into the internal table of cranial bone. For example, the human brain shows a torque growth in which, for right-handers, there is a left occipital petalia combined with a right frontal petalia. If one looks dorsally at a human brain of a right-handed person, one will often see that the left occipital extends further back than the right, while the right frontal width appears somewhat wider than the left. The opposite condition holds for true left-handers. It is important to realize that these relationships are correlational only, and not obligatory (see Holloway and de Lacoste-Lareymondie, 1982). While pongid brains certainly show asymmetries (with Gorilla gorilla having the most asymmetrical cerebral petalias; see Groves and Humphrey, 1973), they almost never show the typical human pattern of combined occipital and frontal petalias described above. The fossil hominids, to the extent that both sides of the cranial bone are available and without significant distortion, can provide speculative suggestions regarding a limited degree of their cognitive capacities. Most of the work done on these asymmetries has been only crudely quantitative, as exact measures of the asymmetries are difficult to obtain without sophisticated specialized equipment. We believe CT-scanning and 3-D reconstructions will be extremely valuable techniques for providing more reliable metric observations on these potentially very significant asymmetries. In addition we are studying the possibility of asymmetries in the Broca’s cap regions of the fossil hominid endocasts. Our data thus far suggest that where the left Broca’s cap region in modern Homo appears, the asymmetries are larger than on the right, at least for most right-handed individuals (Broadfield et al., 2001; Broadfield and Holloway, 2002). Broca’s cap (a.k.a. frontal cap, orbital cap), introduced by Raoul Anthony (1913) when describing the La Quina brain endocast, refers to the third inferior frontal convolution, which includes primarily Brodmann’s areas 47 and 45 and a portion of area 44. We are intrigued that such asymmetries have been clearly shown for modern Homo sapiens by Amunts et al. (1999, 2003) and Foundas et al. (1996, 1998). They appear also on the small sample of brain

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casts that we made for modern Homo sapiens (Broadfield and Holloway, 2002), and appear on a number of Indonesian endocasts of the morph currently designated as Homo erectus (Broadfield et al., 2001). Needless to say, since these regions in modern Homo have a clear involvement in parts of language processing, we are intrigued that similar asymmetries are seen in specimens perhaps as old as 2.0 million years (MY ), as in KNMER 1470, for example. This idea has recently been challenged by Cantalupo and Hopkins (2001), who claim, on the basis of MRI images, that chimpanzees show such asymmetries as well. However, as Sherwood et al. (2003) demonstrate using cytoarchitectonic methods, the sulcal patterns in apes do not match the cytoarchitectonic differences found between Brodmann’s areas 44 and 45. This leads us to conclude that MR images of sulcal patterns do not describe important functional differences, although it is important to start with gross morphological patterns of the cerebral cortex. We believe that it will be necessary to quantify the cytoarchitectonic differences between Broca’s areas 44 and 45, and possibly 47, and between left and right sides in both apes and modern humans before this issue can be settled. The recent paper by Amunts et al. (2003) demonstrates clear asymmetry in cytoarchitectonic areas 44 and 45 of Brodmann as early as age 1 in infants, increasing significantly in area 45 with age and thus perhaps demonstrating both neurogenetic and microstructural plasticity related to language functions.

Meningeal Patterns and Blood Supply (Arterial and Venous) The dura mater is supplied with blood vessels, known as meningeal vessels, and these frequently leave imprints on the internal table of bone. The patterns of these vessels have some importance as taxonomic markers (e.g., see Saban, 1984; Grimaud-Herv´e, 1997), although this remains controversial. These vessels, as far as we know, have nothing to do with cerebral structure and function. However, the major venous vessels such as the longitudinal, transverse, and sigmoid sinuses provide important taxonomic information, and here too there is considerable speculation regarding their functional significance. As we will show later when we discuss the occipital/marginal (OM) sinus, which as been used as a claim to “robust” australopithecine membership (White and Falk, 1999; Falk et al., 2000; Holloway et al., 2002), the meningeal vessel structure appears in all primate taxa, including modern humans. As the true arterial blood supply to the brain arrives via the carotid arteries, the actual blood supply to the brain is almost

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totally internal to the surface and thus not detectable on an endocast. We are delighted that Dr. Grimaud-Herv´e has shared her knowledge of meningeal variations with us in this volume, and that her husband has provided such fine illustrations of these patterns.

Biobehavioral Significance of Brain Endocasts Absolute Brain Size As mentioned above, brain endocasts are not rich sources of information about the structure or functioning of the brain. Aside from size and coarse lobar configurations, such as the presence and placement of the lunate sulcus, or the region of the third inferior frontal convolution usually designated as Broca’s area, or degrees of hemispheric cerebral asymmetries, brain endocasts remain mute testimony to what their once-living cerebral and subcortical contents could do. The human species seems to be particularly attuned to matters of size, whether of the brain or other anatomical parts, and this for a variety of reasons. First, size is something that can be measured, and measurements can either be replicated or not. Intuitively we all assume that the size of something has some relationship to its effectiveness and power (as well as its cost, metabolically), and that we can in essence find the importance of the entity displayed in the property of size variation. Our brains are three to four times larger than those of our closest relative, the chimpanzee, whose brain in turn is roughly three times as large as those of the Old World monkeys, such as macaques and baboons. For brain size in these species, we regard the correlation, however crude, with behavior to be self-evident. We also tend to believe that organs that vary in size and that have some relationship to behavior follow a Darwinian evolutionary model. Indeed, this is basically how we tend to view our own braininess, that our brains became larger, and our larger brain sizes were selected for as we evolved because we were capable of more complex and intelligent behavior. We even recognize that there had to be constraints on this paradigm, at least in terms of two factors, namely metabolic costs and parturition, with the latter having to do with the size of the infant’s head and the pelvic inlet and outlet and the efficiency of bipedal locomotion. The evidence points to our early ancestors of 3 to 4 MYA having brain sizes around 400 ml and our cranial capacities being around 1400 ml; the intermediate values for early and later Homo are, in this view, thought to reflect some natural selective forces operating on brain size and

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intelligent behavior correlated with it. On the other hand, the more micro-evolutionary events in our brain’s evolution are not transparent. There may well have been times when natural selection favored larger body sizes, and the brain, due to its allometric relationship with body-size, increased without selection necessarily acting on behavior. Also, selection for increased body size might have resulted in increased brain size, as the two variates are related. There are problems inherent in simply accepting past brain size as an indicator of increasing behavioral sophistication in the fossil record. If natural selection worked in the past to increase our brain size, isn’t brain size today also being selected for (or against)? And therein lays the rub, so to speak. The variation in modern human brain size, which ranges in weight from 900 to 2000 grams, is roughly the same as the total evolutionary change in brain size from Australopithecus to us, which is about 1000 ml. One of the cardinal lessons human biology has evinced is that variation in modern brain size has no significance for modern human behavior. To believe otherwise is, simply put, discriminating and racist. The conundrum we end up with is how can we explain the evolutionary past if there is no significant behavioral correlation between intelligence (however defined) and our brain size? Assuming that 3 MY separates ourselves from Australopithecus, 1000 ml divided by 3 MY gives a very rough estimate of 0.000333 ml per year, or about 0.00666 ml per generation, if a generation is calculated as 20 years long. It simply eludes our imaginative abilities to believe that even changes of 1 to 10 ml could have any effect on behavior. We cannot even measure what 0.00666 ml of brain tissue might mean in any computational sense. If we go in the reverse direction, and try to argue that 1000 ml has made an enormous difference in our intellect over the past 3 MY, should we expect through uniformitarianism principles that today’s individuals at the low end of brain size (i.e., around 1000 ml), should be considerably less intelligent than those with brain sizes around 2000 ml? Well, in fact, some writers do argue that the difference between a mean brain weight of 1350 grams and 1300 grams is indicative of a difference in intelligent behavior (e.g., see Rushton, 2000, 2002, who has perhaps gone the farthest with this idea). It has been almost uniformly accepted by the anthropological community that the correlation between brain size and intelligence is negligible, and surely insignificant, yielding at most an R coefficient of about 0.25 (e.g., see Van Valen, 1974, who argued that small differences could be important over many generations).

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More recent research, using noninvasive MRI techniques has published correlation coefficients (R) varying between 0.4 to 0.6 with statistical significance in college students (for a review, e.g., see Willerman et al., 1991; Andreasen et al., 1993; Tramo et al., 1998; Anderson, 2003). To this, we can bring forth many objections with the basic concepts of brain size, “intelligence,” statistical comparisons, and the like, and include the fact that men and women differ significantly in brain size (men being on average about 9–10% larger in brain size) but not in terms of intelligence. Of course, a full discussion of this point would take us far beyond the scope of this book; we raise it to show the problems inherent in blithely accepting past brain size as an indicator of increasing behavioral sophistication in the fossil record. This relationship is almost impossible to scientifically demonstrate without comparing our own species’ variability in this regard (or other species), something most scientists are loathe to do. Nevertheless, none of the considerations above will ever deter us from measuring how large/small our fossil ancestors’ brains were. Nor will they prevent us from measuring brain size against time within and between taxonomic levels to attempt to ascertain changes in selection pressures (e.g., see Holloway, 1975, 1981 for specific illustrations of brain size/time models possible).

Relative Brain Size As mentioned at the beginning of this chapter, as primates, we have the largest absolute brain size, but not the largest relatively speaking. Could it be that our relative brain size was really more important in our evolutionary development than our absolute brain size? And, isn’t there a relationship between the size of our brains and our bodies within the primate order? The latter question is clearly answered in the affirmative, as the study of the relationships between sizes of organs and the body—the study of allometry—attests. We know, for example, that when we plot the logs (base 10) of brain and body weights together for all the primates, there is a clear-cut allometric relationship with an exponent of about 0.75 (Martin, 1983), suggesting a metabolic relationship. Relatively speaking, we have about three to four times the brain size expected for a primate of our body size, our brain size being around 2% of our body size. Indeed, knowing our brain and body size allows us to compute a coefficient known as the encephalization coefficient (EQ), by which we can measure ourselves against other animals. Such coefficients are themselves relative, since they depend on the database used to derive the basic brain/body

allometric equations (see Holloway and Post, 1982, for discussion of the relativity of relative brain measures). One thing is certain, however: whichever databases we use, whether for all primates, all mammals, or just the great apes, we (modern humans) always end up with comforting finding that we have the highest value. It must be underlined that EQs are relative, depending on the data set chosen. For example, some of the most cited EQs are those resulting from Jerison’s (1973) equation, EQ =

Brain weight (of any species) 0.12 × Body weight0.66

Humans have an EQ of 6.91, the chimpanzee 4.02, and the gorilla 1.8, using Jerison’s equation and the values for body and brain weights in Holloway and Post (1982: 63). It should be remembered here that Jerison purposefully fitted a slope of 2/3 (0.66) to his polygon, including the “higher vertebrates” and that that slope was not empirically determined, in contrast to Martin’s (1981, 1983; see also 1990) equation. But, if we use the allometric equation based on 88 species of primates (Bauchot and Stephan, 1969), the constant is different (0.0991) and the exponent is 0.76. In this case the human EQ is 5.46, the chimpanzee 2.25, and the gorilla 0.939. Since the human animal remains the most encephalized primate known, we offer an EQ equation that provides an immediate percentage of the modern human value for each species of primate: EQ =

Brain weight 1.0 × Body weight0.6409

In this example, the human EQ is 100, or unity, based on an average brain weight of 1330 grams for modern Homo sapiens and an average body weight of 65,000 grams (Tobias, 1971). We further assume that if there is no body weight, there is no brain weight, and the regression line falls through the origin. By this equation, the chimpanzee EQ is 39.5%, and the gorilla EQ is 19.1%. To obtain these EQs, we used a chimpanzee brain weight of 420 grams, and a body weight of 46,000 grams. For gorilla, we used an average brain weight of 465 grams, and a body weight of 165,000 grams (these are the values given by Stephan et al., 1981). The value of brain weight for chimpanzee is on the high side, the value for gorilla on the low side (see Holloway and Post, 1982, for further discussion).

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Of course, when the EQs calculated by a particular equation are divided by the human EQ value (whether Jerison’s, Martin’s, Holloway and Post’s, etc.), the results can be expressed as a percentage of human value. Rank order correlation of these results provides a correlation of at least 0.9, indicating a close but not perfect agreement. Thus the rank of EQs for some animals changes depending on the database used. We prefer the homocentric equation simply because it gives in percent an immediate EQ of the average modern human value. However, we wish to make the point here that EQs do not evolve. EQ values may increase or decrease for an animal line depending on the equations used, but what is changing are brain/body weight variables, which may or may not be under selection pressures at any given time. The application of these equations to particular fossil hominids requires an accurate estimation of body weights, and in a given living population these vary considerably. For example, based on a data set of 48 chimpanzee brain and body weights, the EQs (using Holloway and Post’s Homocentric equation) varied between 29% and 57% of the modern human value of 100%, while for 23 gorillas, the EQs varied between 17% and 37%. Using the Danish brain weight sample discussed in Holloway (1980), and culling out extreme body weights, adult human EQs varied between 70% and 145%, the average and modal value being 100%. Consequently we should expect some of our early hominids to overlap with chimpanzee EQ values.

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In our quest to better understand the changes in our own “encephalization” through time, we require not only accurate determinations of brain sizes but also of body sizes. The fact is, however, that none of our fossil finds, aside from whole skeletons, ever provide us with enough material to obtain highly accurate body weights. Much fine work has been done ( Jungers, 1988; McHenry, 1988, 1992; Ruff, 1990, 2000, 2003) in trying to estimate body weights from partial skeletal materials, such as limb bone lengths, using comparative and human skeletal materials where body weights are known, but these still only provide estimators that are less accurate than brain sizes. Nevertheless, a study of these relationships is useful as it has already shown that mid-Pliocene hominids were more encephalized than their more recent pongid-like ancestors. This result alone suggests natural selection to have worked on relative brain size early in our evolutionary history, since these hominids had roughly the same brain sizes as our largest chimpanzees, which is around 400 to 450+ ml. To the degree that data are available, we will discuss the relative brain sizes and possible advances in encephalization in a later chapter on specific hominid taxa.

The Reduction of Primary Visual Cortex and the Lunate Sulcus One of the few measurable differences between the gross neuroanatomy of human and pongid brains, aside from overall size, is that the primary visual striate cortex (PVC)—Brodmann’s area 17—is relatively reduced in volume in the human brain. Figure 5 shows a typical

Figure 5. Log-log plot of volume of the primary visual striate cortex against brain volume.

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log-log plot of the volume of the PVC against the volume of the brain for a collection of different primate species ranging from strepsirhines to modern humans. The correlation is about 0.98, and as is obvious, the loglog transformation provides a satisfying straight line, with the human point departing significantly from the regression line. The departure is 121% for the human value: that is, the human value is 121% less than would be predicted for another primate with the human brain volume. (Incidentally, for such a high correlation coefficient, the least-mean-squares method of regression is preferable over the reduced major axis method.) The prediction for the volume of the lateral geniculate nucleus, from which the optic radiations to the occipital lobe emerge, is 144% greater than actually occurs in the human brain: that is, as with the PVC, the lateral geniculate nucleus is 144% less than expected in the human brain. Since the human animal is not deficient or defective in its vision, this apparent reduction could be a sign that the posterior parietal association cortex (and/or other cortical regions) has relatively enlarged, but we are not aware of any quantitative studies that have explored this notion. In great apes, and in the Haplorhini in general, the PVC is anteriorly bounded by a primary sulcus known as the lunate sulcus (LS). The LS is both always present and very prominently visible in pongid brains but seldom visible in human brains. (See Smith 1904, 1907, who defined the lunate sulcus, and also Connolly, 1950; Levin, 1936; Ono et al., 1990, measured its variability in modern Homo sapiens.) It occasionally (but very rarely) is demonstrable on the brain endocasts of apes and

modern or fossil hominids. Therein lies the difficulty: When, in the course of human evolution, did the PVC become reduced (or the posterior parietal association cortex increased) in volume from a pongid to human condition, and can the change be demonstrated in the fossil hominid record? Can we use the lunate sulcus as a guide to the relative decrease of PVC and thus a relative increase in posterior parietal association cortex? As we demonstrate in this book, the mid-Pliocene hominids show evidence of this important cortical reorganization. In particular, the new Stw 505 specimen from Sterkfontein, South Africa, shows an indisputable LS in a more posterior position than found on any pongid brain or pongid brain endocast that we have examined. This means, of course, that while both absolute and/or relative brain weights for early hominids may or may not exceed common chimpanzee brain weight values, the cortex had become reorganized prior to any significant enlargement, such as found in the genus Homo (see Table 2 for a summary of hominid brain reorganizational changes, and also Holloway et al., 2003, for discussion and examples of this variability in chimpanzee brains).

The Frontal and Prefrontal Lobes Given the apparent steepness of the modern human forehead, the lack of such steepness in chimpanzees and other apes, and the large brow ridges of most hominids, including those currently aligned with the Neanderthal calvarium, it would seem intuitively correct that the frontal lobes of the cerebral cortex, and in particular, their prefrontal portions, would be relatively enlarged in modern Homo sapiens, and that most

TABLE 2 Reorganizational changes in the evolution of the human brain Brain Changes (Reorganization) (1) Reduction of primary visual striate cortex, area 17, and relative increase in posterior parietal cortex (2) Reorganization of frontal lobe (third inferior frontal convolution, Broca’s area, widening prefrontal) (3) Cerebral asymmetries, left occipital, right-frontal petalias (4) Refinements in cortical organization to a modern Homo pattern

Taxa

Time (MYA)

Evidence

A. afarensis A. africanus

3.5 to 3.0 3.0 to 2.0

AL 162-28 endocast Taung child, Stw 505 endocast SK 1585 endocast

Homo rudolfensis Homo habilis Homo erectus

2.0 to 1.8

KNM-ER 1470 endocast Indonesian endocasts

Homo rudolfensis H. habilis, H. erectus ? Homo erectus to present?

2.0 to 1.8

KNM-ER 1470 endocast Indonesian endocasts Homo endocasts (erectus, neanderthalensis, sapiens)

1.5 to 0.10

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of brain evolution has involved the enlargement of the frontal lobe. Countless chapters in neuroanatomy and neurology texts do provide evidence for the frontal lobes’ involvement in complex cognitive tasks, and, indeed, in our veritable humanness. When one looks at the brain endocasts of a series of hominids from the mid-Pliocene to modern humans, it does look like the frontal lobe becomes rounder, higher, and broader—in effect, less pointed. When RLH wrote his dissertation in 1964, he was quite surprised to find from the literature that actual measurements of the frontal lobe by von Bonin (1948) showed that when frontal lobe size was plotted against total brain size for different primates, the resulting slope was a straight 45% degree line, and that the human value did not digress from it (see also Holloway, 1968). Semendeferi and her colleagues later confirmed this observation in several articles (Semendeferi et al., 1997, 2001, 2002) based on MRI image analysis and quantification, and their analyses also extended to portions of the prefrontal cortex, Brodmann’s areas 9, 10, and 13. A similar set of findings, this time using cytoarchitectonic criteria, was published by Uylings et al. (1992) on the orangutan, also a large-brained ape. Slopes for regressions between frontal lobe size and prefrontal size were all very close to 1.0, or almost complete isometry, with the human points falling almost perfectly on the regression line. Nevertheless, one finds estimates such as Deacon’s (1997) that the human prefrontal lobe is 202% larger than an ape’s, a finding based on calculations made from Brodmann’s earlier 1909 observation on

ENDOCASTS

cytoarchitectonic homologues between macaque, chimpanzee, and humans. No one has confirmed independently any of those earlier findings, and we believe the recent findings of Semendeferi and colleagues should lay this issue to rest once and for all. However, Schoenemann (1999) believes the surface area of the prefrontal lobes is twice as large in humans than in non-human primates. Indeed, specimens such as the Neanderthal calvarium and La Ferrassie cannot be shown to have had smaller frontal lobes than modern Homo sapiens, as Holloway (1985) initially tried to show. Later, Bookstein et al. (1999) showed, using complex morphometric analyses, that the forehead roundness of Neanderthals and modern Homo sapiens does not differ in any significant way. Of course, with a three to four fold expansion of brain size from mid-Pliocene hominids to Homo sapiens (Table 3) it can be argued that the human frontal lobe and its prefrontal portions must have increased in size absolutely. If one believes in Rubicon models, then perhaps once the absolute volume surpassed some critical level, the behavioral hallmarks of humanness suddenly emerged, namely language, forethought, planning, inhibition of impulsive behavior, symbolic behavior, and much else. This is similar to the “spandrels” view promulgated by Gould and Lewontin (1979). This position views such behavioral developments as mere epiphenomena without any basis in past selection pressures. Such a view has numerous ontological problems as it ignores many aspects of both the fossil hominid and comparative neuroanatomical evidence that proves that

TABLE 3 Summary of size changes in human brain evolution Brain Changes (Brain Size Related) (1) Small increase, allometrica (2) Major increase, rapid, both allometric and nonallometric (3) Small allometric increase in brain size to 800–1000 ml (assumes H. habilis was KNM 1470-like) (4) Gradual and modest size increase to archaic Homo sapiens, mostly nonallometric (5) Small allometric reduction in brain size among modern Homo sapiens a

Taxa

Time (MYA)

A. afarensis to A. africanus A. africanus to Homo habilis Homo habilis to Homo erectus

3.0 to 2.5

Homo erectus to Homo sapiens Neanderthalensis Homo s. sapiens

0.5 to 0.10

2.5 to 1.8 1.8 to 0.5

0.015 to present

Evidence Brain size increases 400–450 ml, 500+ ml KNM-1470, 752 ml (ca. 300 ml) Homo erectus brain endocasts and postcranial bones (e.g., KNM-WT 15000) Archaic Homo and Neanderthal endocasts 1200 – 1700+ ml Modern endocranial capacities

Allometric means related to body size increase or decrease, while nonallometric refers to brain size increase without a concomitant body size increase.

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reorganization occurred during human evolution. We reject this view in favor of a view that sees selective forces acting upon different regions of the brain and its underlying hardwiring, with ontogenetic development occurring at different times in the course of human evolution (see Holloway, 1979). This is in essence what we mean by mosaic brain evolution. As we will show, Broca’s regions do appear to have undergone an evolutionary development in Homo, with the modern Homo condition of asymmetries in that region appearing in many of the specimens currently assigned to Homo erectus (e.g., Sm 3) brain endocasts, and possibly even earlier (e.g., KNM-ER 1470).

The Temporal Lobe Recently Rilling and Seligman (2002) have shown that the human temporal lobe is about 20% to 30% larger than would be expected for a primate with its brain weight. This study is based on several specimens for each species, whereas the original Stephan et al. (1981) data set was based on 45 species, including Homo, but with one data point for each species. Rilling and Seligman were also able to show, using paired t-tests, that the differences between predicted and observed temporal lobe volumes were statistically significantly larger in modern humans. This represents yet another example of reorganization of the cerebral cortex. In time we expect these workers to indicate whether the parietal lobes have also undergone an increase in relative size in Homo sapiens. In sum, we believe that the judicious use of brain endocasts can enlarge our understanding of the course of hominid brain evolution as they reveal that changes in size, both absolute and relative, and reorganization, including asymmetries, were important evolutionary developments at different times during human mosaic brain evolution. That evolution appears to have involved far more than simple brain size enlargement, and such reorganizational events should not be ignored.

Endocranial Morphology and Terminology Here we outline the general morphologies exhibited on endocasts based on features visible in extant chimpanzees and modern humans (Figs. 6–10). While the morphologies presented in the following images may be visible on the exhibited endocasts and brains, the reader is reminded that there are large variations in the

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features exhibited on any endocasts. Moreover the different specimens discussed in this volume are often incomplete, so we lack the range of features often seen in a detailed, complete endocast. As with the first two volumes of this series, we have followed the general outline of Schwartz and Tattersall (2002, 2003, in press) by using morphs (a group of biological organisms that differs in some morphological respect from other groups) to avoid systematic implications in describing the different endocasts, except when referring the reader to earlier arguments concerning the taxonomy of a fossil within the Significance section of an entry. This is because, despite our own opinions on systematics, the descriptions of the individual endocasts should be devoid of opinion that may lead the reader to view one feature as absolutely more important than another. In other words, it is up to the reader to determine the meaning of the features discussed here. Of course, while we do lend our opinion regarding systematics and taxonomic designations at the end of this volume, endocranial features on their own rarely, if ever, lend themselves to promoting one taxonomy over another. The terms below are features present on endocasts (for the definition of endocast, see above). These terms are not, in general, unique to endocasts but are derived from anatomical structures, and in many cases specific neuroanatomical structures, of the brain or endocranium. Since the soft tissue structure does not preserve on an endocast the reader should be aware that the identified structures are hard representations of underlying structures and not the anatomical feature present in a living organism. Thus the definitions below describe the feature as it occurs on an endocast: Bec. The inferior terminus of the frontal region that would correspond to that portion overlaying the cribriform plate of the ethmoid bone. Encephalization Quotient. Measure of the amount of brain tissue that an animal possesses beyond that expected for its body weight, based on some taxonomic series. Endocast. Cast, either natural or human-made, of the endocranium. Gyrus. A convolution of the brain. A raised ridge between grooves, sulci, and fissures of the brain. Lunate Sulcus. Sulcus that usually defines the anterior limit of the primary visual striate cortex in nonhuman primates. This structure is usually fragmented in humans.

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Figure 6. Lateral view of a modern human brain (top) and a modern human endocast (bottom), demonstrating the observable anatomical landmarks of both (casts’ source, Kronen Osteo).

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Figure 7. Dorsal view of a modern human brain (top) and a modern human endocast (bottom), demonstrating the observable anatomical landmarks of both (casts’ source, Kronen Osteo).

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Figure 8. Basal view of a modern human brain (top) and a modern human endocast (bottom), demonstrating the observable anatomical landmarks of both (casts’ source, Kronen Osteo).

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Figure 9. Frontal view of a modern human brain (top) and a modern human endocast (bottom), demonstrating the observable anatomical landmarks of both (casts’ source, Kronen Osteo).

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Figure 10. Occipital view of a modern human brain (top) and a modern human endocast (bottom), demonstrating the observable anatomical landmarks of both (casts’ source, Kronen Osteo).

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Meningeal Vessel. An uneven, often branching, ridge that is the result of the meningeal vessels. The principal meningeal vessel in the endocranium is the middle meningeal artery, which arises from foramen spinosum. For further discussion of this feature, see Part 5. Petalia. An indication of differential development of one cerebral hemisphere over the contralateral as measured by the projection of the lobe over the contralateral lobe or by differential width. For example, a right frontal petalia indicates that the right frontal lobe projects anteriorly beyond the left frontal lobe, and/or is wider than the left lobe. In an occipital petalia one occipital lobe would project posteriorly beyond the contralateral. Pole. The end or point of greatest projection of a cerebral lobe. The frontal pole is that part of the frontal region that projects most anteriorly. The occipital pole is that region of the occipital lobe that projects most posteriorly. The temporal pole represents the terminal or antero-inferior end of the temporal lobe. These are for the most part highly homologous structures. Sinus. In endocasts, a raised region that corresponds to the sagittal, transverse, sigmoid, occipital or marginal venous sinuses. The sinuses represent reasonable reference marks. For example, the sagittal sinus lies between the cerebral hemispheres, aiding in the location of the endocast midline. The transverse and sigmoid sinuses represent the superior, anterior, and lateral-most margins of the cerebellum. Sulcus. A groove or furrow between two convolutions or gyri of the brain. Suture Line. A ridge that corresponds and is the result of an overlying suture such as the coronal, sagittal, or lambdoidal sutures of the skull.

Descriptive and Figure Format Each entry is presented following the below format: Gross Description. An overview of the morphology of the endocast, including condition. Volume and Method. Known volumes and the methodology, if available, as to how the volume was ascertained. Reliability of the volume estimate. Endocast Details. Specific morphology observable on the endocast. Morphometric Data. Linear and chord measurements. Significance. Importance of the endocast for the interpretation of human brain evolution

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Views of each endocast are presented in a single figure in the following format: Top row from left to right: left lateral view, right lateral view. Middle row from left to right: dorsal view, basal view. Bottom row from left to right: frontal view, occipital view.

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Dudek BC, eds, Development and Evolution of Brain Size: Behavioral Implications. New York: Academic Press, pp 59–88. Holloway RL. 1980. Within-species brain-body weight variability: a reexamination of the Danish data and other primate species. Am J Phys Anthropol 53:109–121. Holloway RL. 1981. Culture, symbols, and human brain evolution: A synthesis. Dialect Anthropol 5:287–303. Holloway RL. 1983. Human brain evolution: A search for units, models, and synthesis. Can J Anthropol 3:215–232. Holloway RL. 1985. The poor brain of Homo sapiens neanderthalensis: See what you please . . . In: Delson E, ed, Ancestors: The Hard Evidence. New York: AR Liss, pp 319–324. Holloway RL. 1995. Toward a synthetic theory of human brain evolution. In: Changeux J-P, Chavaillon J, eds, Origins of the Human Brain. Oxford: Clarendon Press, pp 42–54. Holloway RL. 1996. Evolution of the human brain. In: Lock A, Peters C, eds, Handbook of Human Symbolic Evolution. New York: Oxford University Press, pp 74–116. Holloway RL. 1999. Hominid brain volume. Science 283:34. Holloway RL. 2001. Does allometry mask important brain structure residuals relevant to species-specific behavioral evolution? Behav Brain Sci 24:286–287. Holloway RL. 2002. Brief communication: how much larger is the relative volume of area 10 of the prefrontal cortex in humans? Am J Phys Anthropol 118:399–401. Holloway RL, de Lacoste-Lareymondie MC. 1982. Brain endocast asymmetry in pongids and hominids: some preliminary findings on the paleontology of cerebral dominance. Am J Phys Anthropol 58:101–110. Holloway RL. Post DG. 1982. The relativity of relative brain measures and hominid mosaic evolution. In: Armstrong E, Falk D, eds, Primate Brain Evolution: Methods and Concepts. New York: Plenum, pp 57–76. Holloway RL, Yuan MS, Broadfield DC, DeGusta D, Richards GD, Silvers A, Shapiro JS, White TD. 2002. Missing Omo L338y-6 occipital-marginal sinus drainage pattern: ground sectioning, computer tomography scanning and the original fossil fail to show it. Anat Rec. 266:249– 257. Holloway RL, Broadfield DC, Yuan MS. 2003. Morphology and histology of the chimpanzee primary visual striate cortex indicate that brain reorganization predated brain expansion in early hominid evolution. Anat Rec 273A:594–602. Insel T Shapiro LE. 1991. Oxytocin receptors and maternal behavior. NY Acad Sci 652:448–451. Jerison H. 1973. Evolution of the Brain and Intelligence. New York: Academic Press.

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Jerison HJ. 2002. On theory in comparative psychology. In: Sternberg RJ, Kaufman J, eds, The Evolution of Intelligence. Mahwah, NJ: L Erlbaum Assoc, pp 251–288. Jungers WJ. 1988. New estimates of body size in australopithecines. In: Grine FE, ed, Evolutionary History of the “Robust” Australopithecines. New York: Aldine de Gruyter, pp 115–126. Kochetkova VI. 1978. Paleoneurology. Washington, DC: V.H. Winston. Levin G. 1936. Racial and “inferiority” characters in the human brain. Am J Phys Anthropol 22:345–380. MacLeod CE, Falk D, Mohlberg H, Zilles K. 2002. Patterns of surface shape in great ape endocasts. Am J Phys Anthropol Supp 36:143–142. MacKinnon IL, Kennedy JA, Davies TV. 1956. The estimation of skull capacity from roentgenologic measurements. AJR 76:303–310. Martin RD. 1983. Human Brain Evolution in an Ecological Context. New York: American Museum of Natural History. Martin RD. 1981. Relative brain size and basal metabolic rate in terrestrial vertebrates. Nature 293:57–60. Martin RD. 1990. Primate Origins and Evolution: A Phylogenetic Reconstruction. London: Chapman Hall/Princeton University Press. McHenry HM. 1988. New estimates of body weight in early hominids and their significance to encephalization and megadontia in “robust” australopithecines. In: Grine FE, ed, Evolutionary History of the “Robust” Australopithecines. New York: Aldine de Gruyter, pp 133–148. McHenry HM. 1992. Body size and proportions in early hominids. Am J Phys Anthropol 87:407–431. Ono M, Kubick S, Abernathey CD. 1990. Atlas of the Cerebral Sulci. New York: Thieme. Preuss TM. 2000. Taking the measure of diversity: Comparative alternatives to the model-animal paradigm in cortical neuroscience. Brain Behav Evol 55:287–299. Preuss TM. 2001. The Discovery of Cerebral Diversity: An Unwelcome Scientific Revolution. Cambridge: Cambridge University Press. Preuss TM, Qi H, Kaas JH. 1999. Distinctive compartmental organization of human primary visual cortex. Proc Natl Acad Sci USA 96:11601–11606. Radinsky LB. 1972. Endocasts and studies of primate brain evolution. In: Tuttle R, ed, The Functional and Evolutionary Biology of Primates. Chicago: Aldine/Atherton Press, pp 185–204. Radinsky LB. 1975. Primate brain evolution. Am Sci 63:656– 663. Radinsky LB. 1979. The Fossil Record of Primate Brain Evolution. New York: American Museum of Natural History.

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Humans and great apes share a large frontal cortex. Nat Neurosci 5:272–276. Sherwood CC, Broadfield DC, Hof PR, Holloway RL. 2003. Variability in Broca’s area homologue in great apes: Implications for language evolution. Anat Rec A 271:276–285. Smith GE. 1904. The morphology of the occipital region of the cerebral hemispheres in man and apes. Anat Anz 24:436–451. Smith GE. 1907. A new typographical survey of the human cerebral cortex. J Anat Physiol 41:237–254. Smith GE. 1924. The Evolution of Man. London: Oxford University Press. Stephan H, Frahm HD, Baron G. 1981. New and revised data on volumes of brain structures in insectivores and primates. Folia Primatol 35:1–29. Symington F. 1916. Endocranial casts and brain form: a criticism of some recent speculations. J Anat Physiol 50:111– 130. Tobias PV. 1971. The Brain in Hominid Evolution. New York: Columbia University Press. Tobias PV. 1991. Olduvai Gorge. Vols 4A, 4B: The Skulls, Endocasts, and Teeth of Homo habilis. Cambridge: Cambridge University Press. Tramo MJ, Loftus WC, Stukel TA, Green RL, Weaver JB, Gazzaniga MS. 1998. Brain size, head size, and intelligence quotient in monozygotic twins. Neurology 50:1246–1252. Uylings HBM, van Eden CG. 1990. Qualitative and quantitative comparison of the prefrontal cortex in rat and in primates, including humans. Prog Brain Res 85:31–62. van Valen L. 1974. Brain size and intelligence in man. Am J Phys Anthropol 40:417–423. von Bonin G. 1948. The frontal lobe of primates: Cytoarchitectural studies. Res Publ Assoc Res Nerv Ment Dis 27:67–83. Welker WI. 1990. The significance of foliation and fissuration of cerebellar cortex: The cerebellar folium as a fundamental unit of sensorimotor integration. Arch Ital Biol 128:87–109. White DD, Falk D. 1999. A quantitative and qualitative reanalysis of the endocast from the juvenile Paranthropus specimen L338y-6 form Omo, Ethiopia. Am J Phys Anthropol 110:399–406. Willerman L, Rutledge JN, Bigler ED. 1991. In vivo brain size and intelligence. Intelligence 15:223–228.

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The methods employed to study endocasts will naturally vary depending on the nature of the fossil remains. In the most general terms we attempt to bring the hominid specimen’s brain cast back to a state that would be essentially an immediate postmortem one, namely to correct for any distortion and/or missing parts of the endocast. As the degree of completeness and distortion of the original natural or human-made endocasts vary, so do the methods for attempting to obtain the most accurate and reliable reconstruction. This chapter discusses some of the possible ways of achieving these ends.

Total Endocranial Brain Volume Natural endocasts, for example, those known from South Africa, are seldom distorted, except for the obvious cases of type II and III from Sterkfontein. Taung, Sts 60, and SK 1585 are relatively complete. They were first molded using either latex rubber or silicone-based polymer substances, so that casts, usually of plaster of paris or dental stone, could be used to either add missing parts or carve away projecting adherent matrix (e.g., in the cerebellar-temporal cleft in the Taung specimen). The parts to be added are usually done with modeling clay or plasticene, and the worker tries to follow the missing regions as best as one can. If one side is complete, the requisite amount of plasticene can be added to the missing portions of the other side. When this is done, one must assume complete symmetry in the reconstructed portions. In the case of cranial portions without natural endocasts, the internal table of bone is first usually carefully cleaned and then treated with a penetrant/coating substance, such as Butvar (polyvinyl butyral) or polyvinyl acetate. A mold is next usually made from the cleaned cranial portion. This may be done in pieces because of undercut problems, or as one section that must somehow be stabilized dimensionally. This mold may itself be used as a working cast, usually of plaster, and provide the base for the reconstruction. Alternatively, the reconstruction can proceed directly from the first mold. It stands to reason that the closer the cast is to the original, the more accurate the final product. (See Holloway et al., 2002 regarding the problems of using multiple generations of casts on the omo 3384-6 specimen.) The Human Fossil Record, Volume 3, by Ralph L. Holloway, Douglas C. Broadfield, and Michael S. Yuan. C 2004 John Wiley & Sons, Inc. ISBN 0-471-41823-4 Copyright


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The resulting reconstruction is often sprayed with a waterproofing substance to prevent a potential misreading when the reconstruction is submerged in water from water penetrating the little cracks and fissures in the plaster surface. We are currently using polyurethane for this purpose, though other methods may be used. In addition, if the reconstruction is fitted onto the rubber or silicone cast, it is recommended that the inside of the cast be heavy enough so that the resulting reconstruction will readily sink when submerged in water. The actual measurement of volume relies mostly on Archimedes’ principle, which states that when a body is completely submerged in a fluid, the fluid exerts an upward force on the body equal in magnitude to the weight of the fluid displaced by the body. Given that water has a specific gravity of 1.0, the weight of the water displaced will be the same as the volume of the object submerged. When RLH first started working in South Africa, Kenya, and Indonesia, graduated beakers or cylinders were most often available, and these were often calibrated in intervals of roughly 10 to 20 ml. Thus a beaker would be filled to a certain level with water, the endocast submerged, and the old level subtracted from the new level. We personally find this method not only cumbersome but potentially inaccurate, as one must accept whatever intervals are available and constantly worry about water tension causing the meniscus to adhere to the inside of the beaker or cylinder. Another way of measuring the displaced water is to fill a beaker at least twice as large as the endocast, and catch the run-off water through a spout into another beaker while the endocast is submerged. This run-off water is then weighed, and the beaker’s weight subtracted from the total weight (Fig. 11). Alternatively, one can pour the displaced water into another cylinder calibrated in small intervals of 1 to 10 ml. Most of our measurements are done using a balance scale to weigh the displaced water. We have modified a variety of different size beakers with a run-off spout that is inserted into the neck of the beaker through a drilled hole. The spout is then flexed so that it runs down the inside of the beaker to the base of the container. The modified beakers are filled to capacity, the excess water is allowed to run off until the final drip through the spout, and the endocast is slowly submerged, at the same time collecting the displaced water into a pre-weighed dry beaker. This procedure is repeated three to five times, and the mean weight is used to give a mean volume. Another method directly using Archimedes’ principle is to weigh the reconstructed endocast in air and then

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to find the endocranial volume of OH 7, and Holloway (1972) had similar problems in attempting to find total endocranial volumes for the Makapansgat specimens of the MLD 1 occipital portion and the Sts 19 cranial base portion. In these situations one tries to ascertain what percentage of the total volume is represented in a portion of an endocast. In doing this with a variety of taxa, one hopes to arrive at a percentage figure that is fairly tightly distributed. Tobias’s (1991) discussions regarding the biparietal tunnel of OH 7 provide a detailed description of how this done. (We wish to add, parenthetically, that more useful work could be done in this area, both to expand the available databases for future discoveries and to re-check earlier estimates.)

Endocast Volume Reliability

Figure 11. Demonstration of endocast volumetric estimation method, using water displacement. A: Endocast is submerged in a large beaker filled to the overflow outlet, and the displaced water is captured in a beaker of known weight. B: The beaker holding the displaced water is weighed, giving the weight/volume of the endocast. weigh it in water. The difference should be the volume of the endocast. Accurate and reliable measurements require nonporous endocast materials, clean glassware, clean (preferably distilled) water, and accurate balances and weights. It is always distressing to watch bubbles arise due to improper or incomplete coating of the more porous portions of the endocast, but such are the dangers inherent in paleoneurology.

Partial Brain Endocast Volumes It is often the case that the available cranial portions are too incomplete to allow a reliable total reconstruction of the missing parts, as the missing parts exceed what is present. Tobias and Hughes (see, in particular, Tobias, 1991) ran into this problem when attempting

In the Volume and Method section of each entry in this volume we give our assessment of the reliability of a given endocast volume. The reliability is scored according to method (letter designation) and our evaluation of the given volume (numerical designation). The endocast volumes given here were obtained via one of four methods: (1) direct water displacement of either a full or a hemiendocast with minimal distortion and plasticene reconstruction, (2) determination using a partial endocast as described by Tobias (1967, 1971) and Holloway (1970), (3) extensive plasticene reconstruction amounting to half of the total endocast, and (4) volume calculated from regression formula or estimated on the basis of a few measurements, which are then plugged into formulas such that offered by MacKinnon et al. (1956): V = f [0.5(LWB + LWH )] Here L is maximum length, W is width, B is length from bregma to the posterior limit of the cerebellum, H is the height from the vertex to the deepest part of the temporal lobe, and f is the taxon specific coefficient; X refers to previously published values that have either been confirmed by us or, in certain cases, not. In addition to the endocast method scores, each endocast is scored numerically to indicate our assessment of the reliability of the given volume. These reliability values are evaluated on a scale of 1 to 3 where 1 indicates the highest reliability, 2 that the given volume is generally reliable, and 3 that the given volume has low reliability and should be reassessed.

Brain Endocast Volumes by Formula As with any physical object, there are relationships between the volume and the linear measurements that

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describe the object. Brain endocasts are largely ovoid in shape, sometimes approaching an almost spherical shape, and these relationships can be expressed mathematically, the most obvious being through the radius, diameter, or circumference of the object. Physical anthropology has a long history of using measurements to calculate brain weights and volumes (Pearl, 1905; Isserlis, 1914; MacKinnon et al., 1956; Buda et al., 1975; Sgouros et al., 1999). With the development of multivariate techniques, particularly multiple regressions, one hopes that the volume of an object with a somewhat irregular shape such as a hominid brain endocast can be approximated by a few measurements. RLH (Holloway 1975, 1976, 1978) made a number of attempts to secure formulas that might allow for accurate predictions of endocranial volumes using a few linear chord and arc measurements over the endocast surface. Indeed, the Holloway (1986) description of the Hadar AL 162-28 specimen relied on a prediction made from the biasterionic breadth, based on an extensive collection of ape and hominid (including modern humans) endocasts that RLH made in his laboratory. The proper use of such statistics, however, depends on the sample size and on previous testing for residual values. Considerably more analyses of endocranial measurements should be carried out in the future, and we are providing as many measurements as seem feasible for researchers wishing to explore the predictive merits of our measurements.

Asymmetry Observations and Measures Left-Right Petalias With the publications of LeMay (1976; Galaburda et al., 1978), it became known that there are high correlations between handedness and different patterns of petalias in human brains. The relationship is clearly correlational and not obligate. The petalias most likely represent slightly different velocities of growth of the two cerebral hemispheres, with two regions in particular appearing to be affected: (1) the occipital lobe in both its posterior projection and width and (2) the frontal lobe in terms of its width (Fig. 12). In general, when there is a combination of both left-occipital projection and right frontal width, the growth torque is correlated highly (ca. 90%) with right-handedness (LeMay, 1976). In our study of over 100 pongid brain endocasts, Holloway and de Lacoste (1982) did not find this growth torque pattern of petalias to be present in apes, but the pattern did appear in hominids and modern

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Homo sapiens. To be sure, some individual pongid brain endocasts show asymmetries. Particularly endocasts of Gorilla are well known for their cranial asymmetries (Groves and Humphrey, 1973), but these asymmetries are seldom if ever in combination as in humans. Since we know that human cerebral hemispheres are somewhat specialized for different tasks, we must consider the possibility that petalias in hominids might reflect similar cognitive specializations/organizations as in modern humans. This is where uniformitarianism leads one. Needless to say, only time machines and behavioral testing aboard them of willing hominids can prove such assertions. The petalial asymmetries mentioned are most readily observable from the dorsal view of the endocast, and to date the data have been ordinal in value (i.e., whether or not there is a right or left occipital petalia, and a right or left frontal one). These judgments can, on rare occasions, be somewhat difficult to make, depending on the orientation and placement of the occipital pole on the endocast. In one dorsal orientation there may be a petalia on one side that changes when the endocast is rotated up or down. This sometimes occurs because the true occipital pole on one side is shifted or forced downward by the sagittal sinus leading into the transverse sinus or other mechanical agency. Usually, however, the greater width of the occipital region on one side (most frequently the left) helps resolve this problem. The frontal width is also an ordinal observation, and is often less obvious and thus more difficult to score, than for the occipital petalias. Furthermore it is made taking the frontal lobe as a whole into consideration, and not simply the region of the third inferior frontal convolution or the Broca’s cap region (see below). We have not yet finished our analyses of quantifying these petalias, but the work is in progress. It is also sometimes the case that the right frontal pole is more anteriorly protruding, and thus any measurement of the frontaloccipital poles’ length will not really reflect the petalial pattern. More work in this area is clearly needed.

Asymmetries of the Broca’s Cap Region The literature on asymmetries of the Broca’s cap region, namely the pars triangularis, pars orbitalis, and pars opercularis (Brodmann’s areas 45, 44, and 47) in modern human brains (Amunts, 1999, 2003; Foundas et al., 1995, 1996), suggests that in right-handed subjects the left Broca’s cap region, particularly in area 45, is larger than the right, this based on both histological sectioning and MRI studies. It is, of course, very true that language behavior, and even motor control of vocalization,

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Figure 12. Modern human endocast demonstrating petalias. An occipital petalia is indicated by one occipital lobe being (A) wider and/or (B) protruding posteriorly beyond the contralateral lobe. A frontal petalia is determined by one frontal lobe being (C) wider and/or (D) protruding anteriorly beyond the contralateral lobe.

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are complex functions, and other brain regions, such as the cerebellum, and striatum, have involvement in complex cognitive processes such as the use of symbol systems for verbal communication. No one believes that “language” can be strictly localized to the left Brocas’s cap region, but few would deny the involvement of that region in such behavior, as Paul Broca demonstrated more than a century ago. It is therefore interesting to observe that the brain endocasts of our sample of modern humans shows a consistent pattern whereby the left Broca’s cap region appears more laterally projecting than the right. We also note asymmetries of this region in some of our fossil hominid ancestors, and describe them here. We are prone to believe that these signal possible functional attributes relative to language processing in the hominids displaying these asymmetries. Again, we need that time machine to resolve this issue.

Regional Convolutional Details Detailed convolutional patterns are by far the most difficult part of endocast studies, given the conspiracies of nature and dural tissues which “hide” the gyri and sulci of the once-pulsating cerebral cortex. In addition the sheer degree of variability that exists in higher primates with regard to sulcal morphology, which varies from one hemisphere to another and between individuals, makes the process more difficult. Even monozygotic twins show some degree of variation (Thompson et al., 2001). The secondary and tertiary convolutions are often impossible to discern without ambiguity, and the difficulties are compounded by the fact that different workers have used different terminologies throughout the history of neurological studies. We rely heavily on two publications in particular: Connolly’s (1950) External Morphology of the Primate Brain, and Shantha and Manocha’s (1969) contribution to the first volume of The Chimpanzee, edited by G. H. Bourne. There is no good objective way of following these almost hidden morphologies, but to sit with endocast in hand and compare the slight indentations to the illustrations of convolutions of modern human brains or that of the chimpanzee and try to find the most anatomically reasonable identification. This has been likened to “paleophrenology” by Jerison (1976), and that sometimes is not too far off the mark, except that it IS the morphology we seek and not the functions first! We doubt that our procedures are any different than those used by Schepers (1946, 1950), Smith (1928), Keith

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(1931), Symington (1916), or Clark et al. (1936) to mention but a few examples. There are two regions, in particular, that we examine closely, as these have important relationship to matters of reorganization of the hominid brain: (1) the primary visual striate cortex (PVC) with the reduction of its lateral and dorsal extent on the occipital lobe and (2) the third inferior frontal convolution containing Broca’s region with its developing complexity. With regard to the former, we know from comparative primate quantitative volumetric data that the human PVC is some 121% less than expected for a primate of its brain weight (Holloway, 1997, 2000; Holloway et al., 2001), and we also know that in all pongids yet studied the PVC is anteriorly constrained by the lunate sulcus (Holloway et al., 2003; see also Holloway, 1985, for the history of these arguments). This landmark, when present in humans, is in a very posterior position, and even when not present, the PVC is a small portion of the occipital lobe. The contrast with pongids is indisputable. The question then becomes, When in evolutionary time and history did the PVC become reduced into a more human pattern? This controversy rests at the very base of our understanding of how hominid brains evolved. Similarly, given the importance of Broca’s cap regions to the motor aspects of language, we look at this region with the goal of trying to understand the homologies between hominid brain endocasts and the brains modern humans. To that end, we use the standard terminology of Brodmann’s (1909) cytoarchitectonic areas as ordinal numbers to describe particular brain surface regions of the once underlying cerebral cortex, such as areas 44, 45, and 47 of the third inferior frontal convolution that make up Broca’s areas. When we refer to Broca’s cap, a term introduced by Anthony back in 1913 when describing the La Quina brain endocast, we are referring to the lateral and inferior bulging of that region in general. The “cap” includes areas 45 and 47, and a portion of area 44.

Meningeal Patterns Meningeal patterns have no particular behavioral functional significance, except as servicing the dura mater and internal table of bone. Since their patterns may have some taxonomic consistency (Saban, 1984; GrimaudHerv´e, 1997), we are including meningeal descriptions in this volume. Our descriptions are short, and we are grateful that Dr. Grimaud-Herv´e has provided a

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Figure 13. Endocast measurements.

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chapter (see Part 5) on this topic using from her monograph the line drawn by her husband, Dr. Pascal Herv´e.

Morphometric Analyses We employ both chord and arc measurements of the endocast’s surface in our descriptions (Fig. 13). Whenever possible, we report both left and right sides. For regression analyses, we use the average of left and right sides, or whichever side is most reliable. When we report a measurement preceded by a ca (circa), it represents an approximation. We use this convention for those measurements that span regions of Plasticine reconstruction. Length, breadth (width), bregma-basion, and height measurements are taken with spreading calipers. The height measurement is the maximum height from vertex to the lowest projection of the temporal lobes in the midsagittal plane. This measurement is taken by stretching the tape over the deepest temporal lobe region, and simultaneously placing the spreading caliper ends on the tape and the vertex of the endocast when oriented in a plane through frontal and occipital poles. The bregma-lambda, biasterionic, and bregma-asterion measures are taken with sliding calipers. All arc measurements are taken with calibrated tape. The frontal and occipital poles, as well as points of maximum breadth, are first marked on the endocast surface with pencil and the measurement taken between the appropriate points. The lateral and dorsal length arcs, between the frontal and occipital poles, are placed over whatever regions of maximum convexity are located between the poles, but in a straight manner. The maximum width, almost always on the posterior part of the superior temporal gyrus, is also marked with pencil, and measured with spreading calipers; the arc width is taken with flexible tape between those points over the vertex. The biasterionic breadth is taken as a chord measurement between left and right asterion, when available. We also have included a lateral arc between these points for which the tape is placed across the transverse sinuses or superior cerebellar lobes. The dorsal arc generally follows the dorsal curvature in the region of the lambdoid suture but is, at best, an approximation only. The maximum cerebellar width is taken medially to the widest part of the sigmoid sinuses when present, while sigmoid sinus width measures the breadth across the widest lateral portions of the sigmoid sinus.

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Many other measurements can be taken, as one can see from Weidenreich’s (e.g., 1943) papers, Kochetkova’s (1978) book, or Grimaud-Herve’s (1997) monograph, based on chords and arcs from scaled drawings and projected drawings and tracings. All of our measurements are from the original endocasts and have been selected to pursue the possibility of generating predictive equations that might be useful in studying future partial endocasts. The hope is that combinations of arc and chord measurements will provide rough measures of shape and size relationships useful for prediction of endocranial volumes, either from complete or incomplete endocasts. In order to do so, we have a comparative database of approximately 120+ brain endocasts of pongids (approximately 30–40 brain endocasts each for Pan paniscus, P. troglodytes, and Gorilla gorilla). In addition we have approximately 10 to 15 brain endocasts of modern Homo sapiens made by RLH from the crania in his osteological collection at the Department of Anthropology of Columbia University.

References Amunts K, Schleicher A, B¨urgel U, Mohlberg H, Uylings HBM, Zilles K. 1999. Broca’s region revisited: Cytoarchitecture and intersubject variability. J Comp Neurol 412:319–341. Amunts K, Schleicher A, Ditterich A, Zilles K. 2003. Broca’s region: Cytoarchitectonic asymmetry and developmental changes. J Comp Neurol 465:72–89. Anthony R. 1913. L’enc´ephale de l’homme fossile de la Quina. Bull M´em Soc d’Anthropol Par´ıs March 6, 1913:117–194. Brodmann K. 1909. Verleichende Lokalisationslehre der Grosshirnrinde in ihren Prinzipien dargestellt auf Grund des Zellenbaues. Leipzig: J.A. Barth. Buda FB, Reed JC, Rabe EF. 1975. Skull volume in infants: Methodology, normal values and applications. Am J Dis Child 129:1171–1174. Clark WE Le Gros, Cooper DM, Zuckerman S. 1936. The endocranial cast of the chimpanzee. J R Anthropol Inst 66:249–268. Connolly CJ. 1950. External Morphology of the Primate Brain. Springfield, IL: CC Thomas. Foundas AL, Leonard CM, Gilmore RL, Fennell EB, Heilman KM. 1996. Pars triangularis asymmetry and language dominance. Proc Natl Acad Sci USA. 93:719– 722.

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Foundas AL, Eure KF, Luevano LF, Weinberger DR. 1998. MRI asymmetries in Broca’s area: The pars triangularis and pars opercularis. Brain Lang 64:282–296. Galaburda AM, LeMay M, Kemper TL, Geschwind N. 1978. Right-left asymmetries in the brain. Science 199:852–856. ´ Grimaud-Herv´e D. 1997. L’Evolution de L’encep´ephale chez Homo erectus et Homo sapiens: Cashiers de pal´eoanthropologie. Paris: CNRS Editions. Groves CP, Humphrey NK. 1973. Asymmetry in gorilla skulls: Evidence of lateralized brain function? Nature 244:53–54. Holloway RL. 1970. Australopithecine endocast (Taung specimen, 1924): A new volume determination. Science 168:966–968. Holloway RL. 1972. Australopithecine endocasts, brain evolution in the Hominoidea and a model of hominid evolution. In: Tuttle R, ed, The Functional and Evolutionary Biology of Primates. Chicago: Aldine/Atherton Press, pp 185–204. Holloway RL. 1975. Early hominid endocasts: volumes, morphology, and significance. In: Tuttle R, ed, Primate Functional Morphology and Evolution. The Hague: Mouton, pp 393–416. Holloway RL. 1976. Some problems of hominid brain endocast reconstruction, allometry, and neural reorganization. In: Tobias PV, Coppens Y, eds, Colloque VI of the IX Congress: Les Plus Anciens Hominides. Nice: Pr´etirage, pp 69–119. Holloway RL. 1978. Problems of brain endocast interpretation and African hominid evolution. In: Jolly C, ed, Early Hominids of Africa. London: Duckworth, pp 379– 401. Holloway RL. 1985. The past, present, and future significance of the lunate sulcus in early hominid evolution. In: Tobias PV, ed, Hominid Evolution: Past, Present, and Future. New York: A.R. Liss, pp 47–62. Holloway RL. 1997. Brain evolution. In: Dulbecco R, ed, Encyclopedia of Human Biology, Volume 2 (Bi-Com), 2nd ed. New York: Academic Press, pp 189–200. Holloway RL. 2000. Brain. In: Delson E, Tattersall I, Van Couvering J, Brooks AS, eds, Encyclopedia of Human Evolution and Prehistory, 2nd ed. New York: Garland, pp 141– 149. Holloway RL, de Lacoste-Lareymondie MC. 1982. Brain endocast asymmetry in pongids and hominids: Some preliminary findings on the paleontology of cerebral dominance. Am J Phys Anthropol 58:101–110. Holloway RL, Kimbel WH. 1986. Endocast morphology of Hadar hominid AL 162-28. Nature 321:536.

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Holloway RL, Broadfield DC, Yuan MS. 2001. Revisiting australopithecine visual striate cortex: Newer data from chimpanzee and human brains suggest it could have been reduced during australopithecine times. In: Falk D, Gibson K, eds, Evolutionary Anatomy of the Primate Cerebral Cortex. New York: Cambridge University Press, pp 177–186. Holloway RL, Broadfield DC, Yuan MS. 2003. Morphology and histology of the chimpanzee primary visual striate cortex indicate that brain reorganization predated brain expansion in early hominid evolution. Anat Rec 273A:594–602. Isserlis L. 1914. Formulae for determination of the capacity of the Negro skull from external measurements. Biometrika 10:188–192. Jerison HJ. 1976. Discussion paper: paleoneurology and the evolution of language. Ann NY Acad Sci 280:370–382. Keith A. 1931. New Discoveries Relating to the Antiquity of Man. New York: WW Norton. Kochetkova VI. 1978. Paleoneurology. Washington, DC: VH Winston. LeMay M. 1976. Morphological cerebral asymmetries of modern man, and nonhuman primates. Ann NY Acad Sci 280:349–366. MacKinnon IL, Kennedy JA, Davies TV. 1956. The estimation of skull capacity from roentgenologic measurements. AJR 76:303–310. Pearl R. 1905. Biometrical studies in man. I. Variation and correlation in brain weight. Biometrika 4:13–104. Saban R. 1984. Anatomie et e´ volution des veines m´ening´ees chez les hommes fossiles. Paris: ENSB-CTHS, Editions, pp 1–289. Schepers GWH. 1946. The endocranial casts of the South African ape men. In: Broom R, Schepers GHW, eds, The South African Fossil Ape Men: The Australopithecinae. Transv Mus Mem 2. Transvaal Museum, Pretoria, S. Afriea. Schepers GWH. 1950. The brain casts of the recently discovered Plesianthropus skulls. In: Broom R, Robinson JT, Schepers GWH, eds, Sterkfontein ape-man, Plesianthropus. Transv Mus Mem 4. Transvaal Museum, Pretoria, S. Afriea. Sgouros S, Goldin JH, Hockley AD, Wake MJC, Natarajan K. 1999. Intracranial volume change in childhood. J Neurosurg 91:610–616. Shantha TR, Manocha SL. 1969. The brain of chimpanzee (Pan troglodytes). In: Bourne GH, ed, The Chimpanzee: Anatomy, Behavior, and Diseases of Chimpanzees, Vol. 1. Baltimore: University Park Press, pp 187–237. Smith GE. 1928. Endocranial cast obtained from the Rhodesian skull, British Museum of Natural History. In: Pycraft

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WP, Smith GE et al., eds, Rhodesian Man and Associated Remains. London: British Museum (Natural History), pp 52–58. Symington F. 1916. Endocranial casts and brain form: a criticism of some recent speculations. J Anat Physiol 50:111– 130. Thompson PM, Cannon TD, Narr KL, van Erp T, Poutanen VP, Huttunen M, Lonnqvist J, Standertskjold-Nordenstam CG, Kaprio J, Khaledy M, Dail R, Zoumalan CI, Toga AW. 2001. Genetic influences on brain structure. Nat Neurosci 4:1253–1258.

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Tobias PV. 1967. The evolution of the human brain: some notes toward a synthesis between neural structure and the evolution of complex behavior. Gen Sys 12:3–19. Tobias PV. 1971. The Brain in Hominid Evolution. New York: Columbia University Press. Tobias PV. 1991. Olduvai Gorge, Vols 4A, 4B: The Skulls, Endocasts, and Teeth of Homo habilis. Cambridge: Cambridge University Press. Weidenreich F. 1943. The skull of Sinanthropus pekinensis: A comparative study on a primitive hominid skull. Paleontol Sinica, ns D10:1–485.

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This reconstruction provided a mean endocranial volume of 450 ml, using water displacement technique. Given the undistorted nature of the dorsal surface and the ability to follow cerebral curvatures to provide a basal reconstruction, we believe the volume estimate to be A1-2 in reliability.

BOU-VP-12/130

Gross Description A relatively complete and undistorted dorsal portion of a brain endocast, with few if any convolutional details available from the internal table of cranial bone. The entire base is missing from roughly the lambdoid suture, as are both temporal lobes, and the orbital surface of the frontal lobe. The dorsal curvature and relatively rounded frontal lobes give it a different appearance than those from Sterkfontein (e.g., Sts 5) and even more different when compared the robust forms (e.g., OH 5, SK 1585).

Endocast Details No details can be provided regarding cerebral morphology or asymmetries, as the relevant portions from both sides are not available. As for meningeal vessels, the left parietal lobe shows a clear meningeal vessel coursing posteriorly from the posterior temporal lobe, and a smaller branch about 1 cm anterior to it.

Morphometric Data

Volume and Method

Despite the incompleteness of this endocast, the undistorted condition allows for relatively accurate assessment of certain of the measurements. The chord length of the left side from frontal (present) to occipital poles is ca. 120 mm, and the same for the right side, given that the reconstructions of the occipital poles were necessarily made symmetrical. The lateral left arc length is ca. 150 mm, and the right is the same. Dorsal arc lengths are ca. 180 mm left and ca. 170 mm right, the left dorsal curvature being somewhat higher than the right. The maximum chord breadth, at points on what would be superior temporal lobe, is ca. 90 mm. The dorsal breadth arc over vertex is estimated to be about ca. 165 mm between the two chord breadth points.

The reconstruction for this endocast was done on a plaster cast provided by Dr. T. White and his colleagues. The reconstruction was effected in plasticene, following the contours of the undistorted dorsal half of the endocast. The basal portion was sculpted using all available australopithecine basal portions as a guide to achieve realistic and probable shapes and sizes for the missing frontal bec region, the temporal lobes, brain stem, cerebellar lobes, and a small portion of the occipital lobes. The Human Fossil Record, Volume 3, by Ralph L. Holloway, Douglas C. Broadfield, and Michael S. Yuan. C 2004 John Wiley & Sons, Inc. ISBN 0-471-41823-4 Copyright


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The bregma-basion is estimated to be between 80 and 85 mm, while the maximum height over vertex is estimated to be about 83 mm. The bregma-asterion chord is estimated at ca. 93 mm (left side) and the arc at ca. 120 mm. The biasterionic breadth is ca. 70 mm.

Significance The overall shape of the Bouri endocast, currently assigned to Australopithecus garhi, is concordant with other observations on the cranial and dental remains that this likely represents a different species of the genus Australopithecus. The frontal poles, and available prefrontal orbital margin, provide a rounded, less pointed contour than found in either specimens currently designated as Australopithecus africanus from South Africa, or certainly any of the “robust” forms from either East or South Africa. The small size of the brain endocast

is in the middle of the South African Pliocene gracile range. Without accurate assessments of postcranial remains to calculate a body weight, the encephalization of Bouri endocast remains unknown.

References Asfaw B, White T, Lovejoy O, Latimer B, Simpson S, Suwa G. 1999. Australopithecus garhi: A new species of early hominid from Ethiopia. Science 284:629–635. De Heinzelin J, Clark JD, White T, Hart W, Renne P, WoldeGabriel G, Beyene Y, Vrba E. 1999. Environment and behavior of 2.5-million-year-old Bouri hominids. Science 284:625–629. Holloway RL. 2002. Brain endocast reconstructions of A. garhi (Bou-VP-12/130) and A. boisei (Konso): Some contrasts. Am J Phys Anthrop Suppl 34:86.

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Figure 14. Bou-VP-12/130 (scale = 1 cm).

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detailed here. We refer to the first fragment as Lucy A and the second as Lucy B.

AL 288-1 MORPH

AL 333-45 This is a relatively undistorted posterior half of an endocast that required reconstruction of the frontal and temporal poles. Minor reconstruction was needed for the foramen magnum region. The left temporal region appears to be somewhat deflected, inferiorly (see Kimbel et al., 1982 for description of the cranial portions).

Gross Description AL 162-28 A small posterior portion of an endocast from a point roughly at the level of bregma to midcerebellar lobe in length, and from a portion of temporal squamous suture on the left side to midparietal on the right. (See Kimbel et al., 1982 for description). The internal table of cranial bone is very well preserved, and important convolutional details appear, making this one of the most important brain endocast portions for early hominids in addition to the famous Taung child specimen and Stw 505. It is also one of the most controversial specimens.

AL 333-105 This is an endocast of the basal portion of the brain of an infant, briefly described in Holloway (1978, 1983a, b). The entire dorsal region is missing, and the base is distorted.

AL 444-2 The endocranial portions of most of the frontal, parietal, and occipital lobes, including the cerebellar lobes, and inferior portions of the temporal lobes are somewhat distorted. The brain stem, superior temporal lobes, and rostral orbital surface of the frontal lobe required minimal plasticene reconstruction. The condition of the internal table of bone is poor, and there are no convolutional details.

AL 288-1 There are only two very small endocast fragments for this individual, and they unfortunately do not adjoin. There is a small fragment of occipital and parietal lobe, with a small portion of the mostly right superior part of the cerebellar lobe, which will be described here. The second portion, somewhat larger, is a part of the left parietal showing some of the terminal meningeal vessels. This fragment is devoid of details and will not be

Volume and Method AL 162-28

The Human Fossil Record, Volume 3, by Ralph L. Holloway, Douglas C. Broadfield, and Michael S. Yuan. C 2004 John Wiley & Sons, Inc. ISBN 0-471-41823-4 Copyright


The volume of this endocast approaches 400 ml, but too much of the remaining brain is missing to effect a

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reliable reconstruction. The volume estimates have been made largely on the basis of comparison with South African specimens such as Taung and STS 60. A volume estimate of less than 385 ml was given by Falk (1983a, b). We believe the volume to be between 385 and 400 ml.

AL 288-1 There is not enough material present to hazard more than a guess, which we believe would be very similar to that for the Hadar AL 162-28 specimen, that is, between 375 and 400 ml maximum. We base this estimate on the similar size of the occipital portions of the two individuals.

AL 333-45 As reported in Holloway (1983a), the estimated endocranial volume is between 485 and 500 ml. The reliability is A2. The 485 ml figure was based on a regression formula applied to the biasterionic breadth. The 500 ml value is from the first endocast reconstruction, and a second one is now in progress.

AL 333-105 Plasticene was added to the basal portion to affect a total volume, which provided a volume estimate of 320 ml. Given its infant status, we expect an additional 20– 25% growth to obtain an adult size, and 400 ml is our estimate for the adult size. We estimate the reliability as A3, signifying that a small portion of plasticene was added but that given both the distortion and the infant status, we must speculate heavily regarding its adult size.

AL 444-2 Our (RLH and MSY ) estimates, based on repositioning the endocranial portions, is 550 ml. Using hemiendocasts portions, RLH arrived at a volume of 545 to 560 ml. Water displacement was used in both cases. We regard the reliability as A1.

Endocast Details AL 162-28 As rendered by John Gurche in Holloway (1983c), there are two significant groves that suggest cortical morphology. Groove A (HADAR Fig. 3) is identified as the interparietal sulcus (IP), and groove B a remnant of the lambdoid suture. This groove was not identified as a lunate sulcus (LS), except by Falk (1983b).

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Thus the posterior parietal and anterior occipital lobes show promising convolutional detail, albeit not without controversy. The remaining endocast surface is devoid of convolutional markings. The cerebellar lobes are broken at mid-level; thus there are no remnants of the sigmoid sinus or posterior cerebellar lobes. The transverse sinus is not visible, and there is no trace of a marginal/occipital sinus, whether enlarged or small. There is a small meningeal vein coursing across the left occipital pole, and a tiny vessel on the lower left parietal lobe.

AL 288-1 The most intriguing part of Lucy A’s occipital is the clear presence of the lambdoid suture. The right inferior portion of the suture, just as it meets the right transverse sinus, clearly limits the lateral and inferior portion of the occipital lobe, and there is a distinct groove, moving superiorly along the lambdoid suture and anterior to it, that might be the dorsal limit of the lunate sulcus. The transverse sinus is small in diameter and it is most probable that it received flow from the sagittal sinus, but it is quite difficult to see this clearly because the medial portion of the left transverse sinus appears somewhat larger than the right side. The occipital lobes overhang only slightly the cerebellar lobes. There is not enough of the left occipital lobe to be certain about a petalial pattern.

AL 333-45 Unfortunately, cerebral convolutional details are lacking for this specimen, and landmarks such as the lunate sulcus (LS), interparietal sulcus (IP), or lateral calcarine sulcus (LC) cannot be unambiguously identified. There is a small left occipital petalial, but there is also a large fracture in the lambdoidal suture region of the left occipital pole that might be contributing to this petalia. Superior to the displaced lambdoid suture is a flattened region of the occipital lobe that carries a distinct depression and could be a remnant of the LC. If so, the anterior limit of the primary visual striate cortex (the LS) would be in a primitive, pongid condition. However, no clear IP sulcus abuts against what might be considered an anterior limit to PVC; thus the status of this important region is uncertain. The right sigmoid sinus is fuller than the left side, and both transverse sinuses are visible. It is unclear whether longitudinal sinus flow is to the right or left side. There is definite enlarged marginal/occipital sinus on the left side, commencing from the lateral sinus and coursing toward the sigmoid

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sinus and jugular foramen. There are discernable lateral parafloccular lobules on both sides of the cerebellar lobes, and the internal auditory meatus is seen on both sides within the temporal/cerebellar clefts. The poor quality of internal table of bone militates against any reliable meningeal vessels, except on the inferior aspects of both temporal lobes.

except that the dorsal height of the parietal lobes at vertex appears very high and similar to that seen on SK 1585, a robust form.

AL 333-105

With so much of the frontal and temporal portions missing, metric data are sparse. We estimate A-P chord length to be between 95 and 100 ml, minimally. Arc lengths cannot be estimated. The maximum chord breadth is estimated to be between 85 and 90 mm, with arc breadth 130 mm minimally. The biasterionic breadth is estimated as ca. 62 to 65 mm. The bregmaasterionic chord (left side) is ca. 75 mm and the arc ca. 95 mm. Most important, the distance from the left occipital pole to the posterior part of the IP sulcus is ca. 15 mm, which is roughly 1/2 the distance found in Pan troglodytes.

There is considerable convolutional detail on the inferior frontal, temporal, and cerebellar lobes, but nothing for occipital, parietal, superior, and middle temporal nor dorsal frontal lobes. There is an indication of an enlarged marginal/occipital sinus, which traverses the foramen magnum, and this feature is thus far found only in robust forms. The base of the infant’s cranium was broken and thus the basal portion is severely distorted, with the left temporal lobe folded medially away from the small portion of dorsum containing inferior parietal lobe, which in itself is sprung laterally from the frontal portion. The frontal orbital bec is strongly pressed toward the right side, covering the orbital surface of the right frontal lobe. The right temporal lobe is present only in its anterior portion, and the Sylvian fissure is falsely accentuated by the sprung condition of the squamous suture. The inferior third frontal convolution is missing on the left side but shows interesting details on the right side. The superior portions of the cerebellar lobes are missing; thus the cerebellar form and details regarding sigmoid and transverse sinuses are not available for description. Additionally there is distortion through the foramen magnum region, such that the entire midsagittal orientation is seriously skewed, the left side being skewed posteriorly. The left temporal lobe shows a clear inferior temporal sulcus, a protruding foramen ovale, and a remnant of the foramen spinosum. The same appears on the inferior part of the right temporal lobe, and the middle meningeal vessels show a typical anterior and posterior bifurcation. The left temporal/cerebellar cleft shows the auditory nerve. The right frontal Broca’s cap region is strongly protrusive both laterally and inferiorly, but there also appears to be a convincing inferior frontal orbital sulcus at its anterior margin, suggesting that at least in the infant state, there was a retention of a pongid pattern in this region of the brain.

AL 444-2 Aside from the fact that the cerebral occipital poles overhang the cerebellar lobes, little else can be said,

Morphometric Data AL 162-28

AL 288-1 The parietal/occipital section is ca. 65 mm deep, and ca. 54 mm at its widest across the transverse sinuses. The distance, chord, from lambda to superior level of transverse sinus is 26 mm. We estimate the biasterionic chord breadth as between 65 and 70 mm. Johanson et al. (1982) provide a detailed description of the internal surface of the occipital and suggest that there may have been a marginal/occipital sinus.

AL 333-45 All measurements that follow are based on the second reconstruction. The chord length of the left side from frontal to occipital poles is ca. 120 to 125 mm; the right side is ca. 123 mm. The lateral arc length, left side, is 165 mm; the right, 162 mm. The dorsal arc length is 165 mm left and 160 mm right. The maximum chord breadth is ca. 100 mm, and the arc breadth over vertex is ca. 165 mm. The points for these measures are located on the superior temporal gyrus. The bregmabasion chord length is estimated to be ca. 85 to 90 mm, and the maximum height from lowest temporal lobe to vertex is ca. 80 mm. The bregma to deepest cerebellum is ca. 90 mm. The bregma-asterionic chord is ca. 90 mm, the bregma-asterionic arc is ca. 115 mm. The biasterionic breadth is ca. 75 mm. The bregma-lambda chord is ca. 70 mm and the arc ca. 75 mm. The maximum cerebellar width is ca. 78 mm, and the maximum width across the sigmoid sinuses is ca. 82 mm.

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AL 333-105 Given the severe distortions one can only estimate the approximate measurements. The chord length is ca. 115 to 120 mm, but arc measurements are not possible given the distortions. The maximum chord breadth is estimated between 90 and 95 mm with arc breadth between 120 and 130 mm. The maximum cerebellar width, across the sigmoid sinuses, is 68 mm and is the only certain measurement on this endocast.

AL 444-2 The maximum chord length is 128 mm, the lateral arc is 165 mm, and the dorsal arc 178 mm. The maximum chord breadth ca. 99 mm, and arc breadth is 154 mm. The depth from the vertex to the lowest temporal poles ca. 82 mm. The maximum cerebellar width is ca. 86 mm. Additional measurements can be found by Holloway and Yuan in Kimbel, W., Rak, Y., and Johanson, DC. 2004. The Skull of Australopithecus afarensis. Oxford Univ. Press.

Significance AL 162-28 The description by Holloway (1983c) suggested that there are relatively clear indications of an interparietal sulcus, whose posterior end was abutted against a small groove left by the inferior lip of the posterior portion of parietal bone, and that this remnant coincides with the lunate sulcus. It was suggested that if these identifications are accurate, the LS would have to be in a more human-like posterior position than found in any of the living apes, and would be an indication that the brain had undergone an important reorganizational event very early in hominid evolution. Falk (1983b) contested this view. While agreeing that the groove A depicted in the original Nature article was the IP, she claimed that the groove along the lambdoid suture was the LS, and most critically, that it was in a typical pongid-like anterior position. Holloway and Kimbel (1986) responded that Falk’s (1983b) orientation of the endocast was incorrect, and that it had led her to regard the cerebellar lobes as projecting beyond the occipital lobes. Holloway and Kimbel also pointed out that based on several chimpanzee specimens, the length of the Hadar AL 128-62 chord from occipital pole to IP was less than half that found in chimpanzees. Holloway and Shapiro (1992) later demonstrated that by it being a remnant of the temporal squamous suture, one could be more certain that the original

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orientation by Kimbel et al. (1982), Holloway (1983c), and Holloway and Kimbel (1986) was correct. In addition the measurement of 70+ Pan troglodytes brain hemispheres indicates that the distance from the occipital pole to the proposed LS on the Hadar 162-28 specimen (15–16 mm) is almost 5 standard deviations anterior to the average 35 mm distance found in Pan brains, often with cranial capacities equal to or less than that of the Hadar 162-28 specimen (Holloway, 1988; Holloway et al., 2001a, b, 2003). The issue of early brain reorganization at present rests on the correct identification and interpretation of these fragmented endocasts. For a review of the significance of the position of the lunate sulcus in hominids and pongids, see Holloway (1985). (See also our description of the position of the LS in Stw 505 later in this volume, as well as Dart’s (1959) explanation).

AL 288-1 This find, comprised of an almost complete skeleton, was dated to about 3.2 MYA. It demonstrated a small brain, small body size, yet a series of features of the dentition, and in particular the pelvis and knee joint, that established this fossil as a biped with a non-ape jaw. The possibility of a lunate sulcus just anterior to the lambdoid suture is tantalizing. If this should be true, the location would be in a relatively posterior position compared to the common chimpanzee, P. troglodytes. Too little of the posterior portion is available to be absolutely certain that this depression is indeed the lunate sulcus.

AL 333-45 As is often the case with early hominid brain endocasts, this specimen is a frustrating mix of characteristics that suggests a derived condition from the typical pongid pattern. The main significant finding is that the cranial capacity approaches 500 ml, suggesting, in comparison with other Hadar specimens such as AL 162-28 and “Lucy,” considerable sexual dimorphism in brain size as well as in the dentition and postcranial skeleton. The slightly sprung left occipital lambdoidal region leaves the question of a left occipital petalia moot. Such an observation would indicate some early cerebral asymmetry, possibly reflecting cortical reorganization. We must await the discovery of new specimens to confirm these points.

AL 333-105 This is a rare find, given the paucity of basal portions of hominid endocasts as well as an infant status. It is

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highly frustrating that the distortions are so strong and displace rare and valuable mensuration.

AL 444-2 Despite the distortion this is one of the largest gracile forms of the morph currently designated as A. afarensis ever found. This specimen will be important to the analysis of sexual size dimorphism in these hominids. The similarity to robust forms (as represented by SK 1585 and OH 5) is very clear, and suggests that members of the clade to which AL 444 belongs were surely ancestral to them.

References Dart, R. 1959. Adventures with the missing link. Philadelphia: The Institutes Press. Falk, D. 1983a. Cerebral cortices of East African early hominids. Science 222: 1072–1074. Falk D. 1983b. Hadar AL 162-28 endocast as evidence that brain enlargement preceded cortical reorganization in hominid evolution. Nature 313:45–47. Holloway RL. 1978. The relevance of endocasts for studying primate brain evolution. In: Noback CR, ed, Sensory Systems in Primates. New York: Academic Press, pp 181–200. Holloway RL. 1983a. Human paleontological evidence relevant to language behavior. Hum Neurobiol 2:105–114. Holloway RL. 1983b. Human brain evolution: a search for units, models and synthesis. Can J Anthropol 3:215–232. Holloway RL. 1983c. Cerebral brain endocast pattern of Australopithecus afarensis hominid. Nature 303:420–422. Holloway RL. 1985. Les moulages endocrˆaniens des hominid´es fossiles: L’aube de l’humanite. Science:36–45. Holloway RL. 1988. Some additional morphological and

metrical observations on Pan brain casts and their relevance to the Taung endocast. Am J Phys Anthropol 77:27–33. Holloway RL, Kimbel WH. 1986. Endocast morphology of Hadar hominid AL 162-28. Nature 321:536–537. Holloway RL, Shapiro JS. 1992. Relationship of squamosal suture to asterion in pongids (Pan): relevance to early hominid brain evolution. Am J Phys Anthropol 89:275–282. Holloway RL, Broadfield DC, Yuan MS. 2001a. Revisiting australopithecine visual striate cortex: newer data from chimpanzee and human brains suggest it could have been reduced during australopithecine times. In: Falk D, Gibson KR, eds, Evolutionary Anatomy of the Primate Cerebral Cortex. Cambridge: Cambridge University Press, pp 177– 186. Holloway RL, Broadfield DC, Yuan MS. 2001b. The parietal lobe in early hominid evolution: Newer evidence from chimpanzee brains. In: Tobias PV, Raath MA, MoggiCecchi J, Doyle GA, eds, Humanity from African Naissance to Coming Millennia. Florence: Florence University Press, pp 365–371. Holloway RL, Broadfield DC, Yuan MS (2003) Morphology and histology of the chimpanzee primary visual striate cortex indicate that brain reorganization predated brain expansion in early hominid evolution. Anat Rec 273A:594– 602. Holloway RL, Yuan MS. (In press). Endocranial morphology of AL 444-2. In Kimbel W, Rak Y, Johanson DC, eds, The Skull of Australopithecus afarensis. Oxford: Oxford University Press. Johanson DC, Lovejoy CO, Kimbel WH, White TD, Ward SC, Bush ME, Latimer BM, Coppens Y. 1982. Morphology of the Pliocene partial hominid skeleton (A.L. 288-1) from the Hadar formation, Ethiopia. Am J Phys Anthrop 57:403–451. Kimbel WH, Johanson DC, Coppens Y. 1982. Pliocene hominid cranial remains from the Hadar Formation, Ethiopia. Am J Phys Anthropol 57:453–500.

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Figure 15. AL 162-28 (scale = 1 cm).

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Figure 16. AL 162-28 (not to scale).

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Figure 17. AL 162-28. Occipital view of Hadar AL 162-28 brain endocast of A. afarensis showing the proposed gyri and sulcal pattern suggesting a more posterior, human-like placement of the lunate sulcus. Groove A is the intraparietal sulcus, and Groove B is either the lunate sulcus or a depression created by the inferior lip of the posterior portion of the parietal bone. (See Holloway, 1983a for discussion.)

Figure 18. AL 288-1 (scale = 1 cm). Possible dasal and lateral aspect of the lunate sulcus.

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Figure 19. AL 333-45 (scale = 1 cm).

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Figure 20. AL 333-105 partial cranium (not to scale).

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Figure 21. AL 444-2 (scale = 1 cm).

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effect two independent reconstructions and add some morphological variability to the missing portions that were reconstructed. There were minor differences in the size of the original endocast blanks, amounting to perhaps between 1% and 2% of overall size. Dr. Suwa (pers. comm.) has advised us that the first received endocast blank is the most accurate. After adding the plasticene reconstruction, water displacement yielded a volume of 545 ml on the first reconstruction, and roughly 560 ml on the second, the difference being mainly attributable to reconstructing a larger prefrontal region in the second endocast as well as its minor difference in length and breadth measurements. We regard the first reconstruction as the most accurate, namely 545 ml. The reliability is A1.

KGA-10-525

Gross Description The reconstruction for this brain endocast is made on an almost complete, undistorted silastic endocast blank kindly provided by Dr. Gen Suwa and colleagues. The internal table of cranial bone was almost perfectly preserved, and the reconstruction required reconstruction of a left temporal lobe, based on the almost complete right side, a rostral bec, and prefrontal orbital portion of frontal lobe, which followed the available contours of the remaining prefrontal part of the frontal lobe, a small portion of right cerebellar lobe adjacent to the reconstructed foramen magnum region, and left temporal/cerebellar cleft. (If the author may be permitted a personal observation, this is one of the most beautifully preserved and undistorted australopithecine brain endocast he has seen.)

Endocast Details Although the internal table of bone was beautifully preserved, few convolution details registered through the meninges onto the bony table, except for the meningeal vessels. There is a very slight left occipital and right frontal petalial pattern. Neither of Broca’s cap regions are available, and the occipital region does not provide any cerebral details that form unambiguous evidence for the lunate sulcus placement. The left side of the second endocast blank does show some very slight convolutional detail in this region, posterior to the almost completely fused lambdoid suture, which suggests that the boundary of the lunate, at least in its lateral aspect, is more in a human than pongid position. There is no

Volume and Method We received two silastic rubber endocast molds; the second after some additional cleaning had been done to the original specimen. This gave us the opportunity to The Human Fossil Record, Volume 3, by Ralph L. Holloway, Douglas C. Broadfield, and Michael S. Yuan. C 2004 John Wiley & Sons, Inc. ISBN 0-471-41823-4 Copyright


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trace of the interparietal sulcus, however, so there is little hope of establishing a dorsal limit to the presumed lunate sulcus. Both sigmoid sinuses are full, the right transverse sinus being slightly thicker than the left. We can find no trace of an enlarged marginal/occipital sinus despite White and Falk’s (1999) suggestion that one probably exists. The details of the Konso brain endocast are close to those of OH 5 and SK 1585. The meningeal vessels are very evident on both sides of the endocast, the right side in particular showing that the middle meningeal vessels bifurcate soon after emitting through the foramen spinosum. A clearcut posterior and middle meningeal branch is seen that courses posteriorly and dorsally over the endocast surface. There is an anterior meningeal division also that supplies anterior meninges of the parietal lobe.

Morphometric Data (The numbers in parentheses are the same measurements for the second endocast reconstruction.) The chord length of the left side of the first reconstructed endocast from frontal to occipital poles is 128 mm (135); the right side is also 128 mm (134). The lateral arc length, left, is ca. 160 mm (170), and the right side, ca. 170 mm (168). The dorsal arc length is 165 mm (178) left, and 170 mm (182) right. The maximum chord breath falls on the temporal lobes roughly 35 mm anterior of the sigmoid sinus and is 110 mm (111), and the arc breadth over vertex is 157 mm (155). The bregma-basion chord length is 88 mm (90), and the maximum height from lowest temporal lobe to vertex is 85 mm (88). The bregma-lambda chord is ca. 82 mm; the arc is ca. 91 mm. On the right side, the bregmaasterionic chord is ca. 97 mm; the arc is ca. 115 mm. The bregma-deepest cerebellar chord is ca. 105 mm. The

maximum cerebellar width is ca. 89 mm while the maximum width across the sigmoid sinuses is ca. 92 mm.

Significance Both endocranial cast copies of Konso, currently designated Paranthropus boisei, are superb, undistorted, and relatively complete. The principal importance of this endocast is that it contains details not available for OH5, nor any of the East African, Kenyan robust specimens. The cranial capacity is thus far the largest of this group. It thus adds important information about the morphometric variation of the species. This is because, due to the gap between the facial elements and those of the cranial vault, the original OH 5 specimen has been difficult to reconstruct. Indeed, it reveals a small error in the reconstruction of the brain endocast by Tobias (1967), in that the temporal pole had to be reconstructed. In addition the beautiful preservation of meningeal vessels provides a more secure basis for understanding meningeal variability and its application to taxonomic attributions.

References Holloway RL. 2002. Brain endocast reconstructions of A. garhi (Bou-VP-12/130) and A. boisei (Konso): Some contrasts. Am J Phys Anthrop Suppl 34:86. Tobias PV. 1967. Olduvai Gorge. Vol II: The Cranium and Maxillary Dentition of Australopithecus (Zinjanthropus) boisei. Cambridge: Cambridge University Press. White DD, Falk D. 1999. A quantitative and qualitative reanalysis of the endocast from the juvenile Paranthropus specimen L338y-6 from Omo, Ethiopia. Am J Phys Anthropol 110:399–406.

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Figure 22. KGA-10-525 (scale = 1 cm).

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stem required plasticene reconstruction, and were done by Brown et al. (1993).

KNM-ER 407 MORPH

Volume and Method

Gross Description

KNM-ER 407

KNM-ER 407

This is an almost complete hemi-endocast of the right side. Only the occipital lobe anterior to lambda and the posterior portion of the cerebellum are missing.

The volume was estimated by Holloway to be 510 ml, based on extensive plasticene reconstruction. The reliability is A1-2. Falk and Kasinga (1983) published a volume of 506 ml. Falk et al. (2000) have revised the volume of KNM-ER 407 down to 438 ml, a decrease of 68 ml, but we cannot find a detailed explanation for this finding, except that it is based on a B2 method that pours water into a hemi-cranial cast, rather than a reconstruction of either a full or hemi-endocast. Because of the serious distortions in the petrous portions of the temporal bones, and obvious plastic deformation of the occipital bone near the foramen magnum, we remain skeptical of this new value.

KNM-ER 23000

KNM-ER 732

The KNM-ER 407 endocast represents another possible robust female (as does KNM-ER 732). It is comprised of the left and right cerebellar lobes, occipital lobes up to lambda, distorted temporal lobes, and a small portion of the frontal and parietal lobes mostly on the left side. The distortion makes a reconstruction very difficult.

KNM-ER 732

The volume of 500 ml was determined by Holloway (1973), using water displacement methods on a latex cast prepared in Nairobi, Kenya. The reliability is A1. More recently Falk et al. (2000) have suggested that several specimens of robust australopithecines have inflated brain volumes, and they suggest that the KNMER 732 endocast volume is 466 ml, some 34 ml less than our value. We believe that they have incorrectly assessed the position of the midsagittal plane on this specimen, as they have in the case of SK 1585.

This is a complete dorsal portion of endocast from frontal poles to mid-(right) and inferior (left) cerebellar lobes. The cerebellar-temporal lobe clefts are present on both sides, as well as lateral and posterior portions of the temporal lobes. The temporal lobe poles, rostral prefrontal bec, foramen magnum region, and brain The Human Fossil Record, Volume 3, by Ralph L. Holloway, Douglas C. Broadfield, and Michael S. Yuan. C 2004 John Wiley & Sons, Inc. ISBN 0-471-41823-4 Copyright


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KNM-ER 23000 According to Brown et al. (1993), the volume is 490 ml, by water displacement method. We judge the reliability as A1.

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very clear frontal lobe portion that must issue from the anterior meningeal vessel missing on this specimen.

Morphometric Data KNM-ER 407

Endocast Details KNM-ER 407 Both the distortion and poor preservation of internal table of bone make convolutional details impossible to discern, nor are any meningeal patterns available for description. We cannot comment about possible asymmetries.

We do not have a copy of this endocast in our laboratory, only the cranial fragments. The endocast made by RLH was left in Nairobi. However, a cast made from the plastic cranial replica yields the following approximate measurements. The bregma-lamda chord is ca. 76 mm. The bregma-asterion chord is ca. 87. The maximum width is ca. 100 to 105 mm; the arc measurement could not be made because of missing and displaced endocast portions.

KNM-ER 732 There are no convolutional details on the surface, given the poor preservation of internal table of bone. The frontal lobe is pointed in shape in the prefrontal region as in other robust forms. The sigmoid sinus appears small, and the transverse sinus is difficult to see, but there is a small marginal/occipital sinus traversing the foramen magnum. The dorsal height to vertex is similar to that seen on OH 5 and SK 1585 brain endocasts. Meningeal details are not present except along the margin of the inferior part of the temporal lobe.

KNM-ER 23000 The dorsal segment is not distorted. There is a small left occipital petalia both in length and width. There appears to be a clear right frontal petalia as well. The prefrontal lobes are pointed, and the third inferior convolutions do not show reliable convolutional detail, although it is clearly possible that there is a distinct orbito-frontal sulcus. The parietal and temporal lobes show almost no details, although it is possible that a small portion of the interparietal sulcus is showing on the right side, and it does reach approximately to the lambdoid suture. This latter feature is open, and it is not possible to discern any lunate sulcus. If the identification of the IP is correct, the lunate would be in a position posterior to that of apes but anterior to those of humans. There is a very distinct left transverse sinus, larger than on the left side. There are enlarged occipital/marginal sinuses on both sides, the larger being on the right side, where the transverse sinus is smaller. A strong impression for the auditory nerve is seen in the left temporal-cerebellar cleft. The middle meningeal vessels are clearly represented on the right side, with a

KNM-ER 732 Absent the occipital pole, our reconstruction results in a chord length of ca. 123 mm. The lateral arc is ca. 160 mm, and the dorsal arc is ca. 170 to 175 mm. The maximum chord breadth is ca. 100 mm, and the arc breadth is ca. 170 mm. The bregma-basion chord is approximately 82 mm, and the height from deepest temporal lobe to vertex is ca. 81 mm. The maximum cerebellar width is approximately 95 mm. The biasterionic breadth is estimated to be 78 mm.

KNM-ER 23000 The left chord length between frontal and occipital poles is 127 mm; the right side is 127 mm. The lateral left arc length is 160 mm; the right is 165 mm. The left dorsal arc length is 165 mm; the right side is 170 mm. The maximum chord breadth is 103 mm, and the arc breadth is 155 mm. The bregma-basion length is 96 mm, and the maximum height from lowest cerebellum to vertex is 85 mm. The maximum cerebellar width is ca. 80 mm, and between the sigmoid sinuses is ca. 91 mm. The bregma-lambda chord is ca. 78 mm, and the arc length is ca. 86 mm. The biasterionic breadth is ca. 77 mm. The bregma-asterion chord (rt) is ca. 91 mm, and the arc ca. 108 mm.

Significance KNM-ER 407 The main feature of this endocast is its low endocranial volume, and it appears that it was a female by its size and cranial gracility. Given the disparity of old and new values by Holloway (1983) and Falk et al. (2000),

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this endocast may offer opportunities for further study, perhaps by CT scanning to correct for the distortion.

KNM-ER 732 The cranial fragments are clearly more gracile than either KNM-ER 406, or OH 5, and suggest, as does the lower size of the brain endocast, that this specimen is a female, providing an estimate of sexual dimorphism in the robust forms.

KNM-ER 23000 Relatively complete and undistorted, this endocast is a valuable addition to our understanding of size and morphological variation from the early robust form East African record. At 490 ml, it is at the low end of the range, and perhaps may be useful in giving some indication of the degree of sexual dimorphism, if the sex of the cranium is known. Compared to the OH 5, and the KNM-ER 406 specimens, it is clear that there was brain evolution occurring between early and late robust

australopithecines. The petalial pattern is perhaps too small to be a reliable indication of handedness.

References Brown B, Walker A, Ward CV, Leakey RE. 1993. New Australopithecus boisei calvaria from east Lake Turkana. Am J Phys Anthropol 91:137–159. Falk D, Kasinga S. 1983. Cranial capacity of a female robust australopithecine (KNM-ER 407) from Kenya. J Hum Evol 12:515–518. Falk D, Redmond JC, Guyer J, Conroy GC, Recheis W, Weber GW, Seidler H. 2000. Early hominid brain evolution: A new look at old endocasts. J Hum Evol 38:695–717. Holloway RL. 1973. Endocranial volumes of early African hominids and the role of the brain in human mosaic evolution. J Hum Evol 2:449–458. Holloway RL. 1983. Human paleontological evidence relevant to language behavior. Hum Neurobiol 2: 105–14.

Figure 23. KNM-ER 407 (scale = 1 cm).

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Figure 24. KNM-ER 732 (scale = 1 cm).

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Figure 25. KNM-ER 23000 (scale = 1 cm).

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MLD 37/38

MLD 1 MORPH

We include this specimen here as the undistorted cranial portion allows a reliable estimate to be made of the endocranial volume based on external cranial measurements and regressions from a large database. Dart (1962) originally estimated the volume at 480 ml, while Holloway (1970, 1973) later calculated a volume of 435 ml. Conroy et al. (1990) suggested a cranial capacity of 425 ml based on CT images taken in 0.2 cm slices. We judge the reliability of these methods as D1.

Gross Description MLD 1 This posterior endocast portion has mostly complete cerebellar lobes through the parietal lobe, which is some 30 mm anterior to the lambdoid suture. The temporal and frontal lobes are missing.

MLD 37/38

Endocast Details

This is a posterior portion of the cranium, filled with matrix. No endocast has been made from this specimen. It is undistorted, there is no evidence for a sagittal crest, and bone thickness can be measured.

MLD 1 There is a very slight right occipital petalia; the occipital lobes are unusually rounded, without any sulcal markings. The transverse sinus is stronger on the left side, and the flow from the sagittal sinus appears to be going left. There is a small portion of the superior sigmoid sinus on the left side. Just medial to the right cerebellar lobe is a protrusion, which could be an enlarged marginal/occipital sinus. It is, however, uncertain whether this protrusion is caused by cranial damage or is a true sinus. There are a few terminal branches of the posterior limb of the middle meningeal vessels on the right parietal lobe. The right parietal lobe also appears somewhat fuller than on the left side.

Volume and Method MLD 1 Holloway (1973) estimated the volume as 500 to 520 ml, using a partial endocast method. The reliability is B2-3. The Human Fossil Record, Volume 3, by Ralph L. Holloway, Douglas C. Broadfield, and Michael S. Yuan. C 2004 John Wiley & Sons, Inc. ISBN 0-471-41823-4 Copyright


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MLD 37/38 None.

Morphometric Data MLD 1 The biasterionic chord breadth is 80 mm, and the arc length ca. 120 mm. The maximum cerebellar width is estimated as 90 mm.

morph as Taung, or possibly a specimen of the robust morph similar to those found at Swartkrans. The cast of the occipital bone shows that the superior temporal lines are almost merging some 48 mm anterior to lambda and were probably joined in a more anterior location.

MLD 37/38 The estimate of endocranial volume has good reliability, and thus adds to the sample size of endocranial volumes of gracile forms, such as Taung and Sts 5.

MLD 37/38 The external biasterionic breadth is 84 mm, and the lateral arc of biasterionic breadth is 92 mm. The external bregma-lambda chord is 74 mm, and the arc is 82 mm. Bone thickness is ca. 0.7 to 0.8 mm, as is visible near the coronal suture.

Significance MLD 1 The large size of this endocast, as reflected in both the partial endocast method, as well as the breadth measurements and the possible occipital/marginal pattern, suggest that this is either a large gracile male of the same

References Conroy GC, Vannier MW, Tobias PV. 1990. Endocranial features of Australopithecus africanus revealed by 2- and 3-D computed tomography. Science 247:838–841. Dart RA. 1962. The Makapansgat pink breccia australopithecine skull. Am J Phys Anthropol 20:119–126. Holloway RL. 1970. Australopithecine endocast (Taung specimen, 1924): A new volume determination. Science 168:966–968. Holloway RL. 1973. Endocranial volumes of early African hominids and the role of the brain in human mosaic evolution. J Hum Evol 2:449–458.

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Figure 26. MLD 1 (scale = 1 cm).

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Endocast Details

OH 5

The endocast lacks convolutional detail, except for a small portion of the anterior prefrontal part of the frontal lobe, which shows a strongly pointed condition similar to the KNM-WT 17000 and KNM-WT 13750 endocasts. We believe that the temporal, parietal, and occipital lobes also lack any meaningful convolutional details. The occipital lobes are somewhat puckered (see the description for SK 1585), but that may be more a result of the open lambdoid suture than a function of the lunate sulcus, which if present would be in the lambdoidal sutural zone. We find no evidence for an interparietal sulcus descending posteriorly toward the suture. There is a small left occipital petalia in both length and width, and the occipital poles are highly asymmetrical, with the left being displaced inferiorly relative to the right side. There is a small right frontal petalia in prefrontal length, but the width component is difficult to assess given the missing portions of the posterior part of the frontal lobe at the Sylvian fissure. It seems to be a very small right petalia. The cerebellar lobes are of a triangular shape and appear more advanced than in the gracile australopithecines (Tobias, 1967; Holloway, 1972). Both transverse sinuses are only slightly visible, as are the sigmoid sinuses, but there are conspicuously enlarged marginal/occipital sinuses traversing both sides of the foramen magnum (see Holloway et al., 2002, for comparisons with the Omo L338y-6 brain endocast). The major flow from the sagittal sinus was clearly to the right side, and perhaps mostly to the occipital/marginal sinuses. The foramen magnum is “heart-shaped,” a

Gross Description OH 5 is an almost complete brain endocast, lacking only a very small contact between the facial and cranial elements. This gap means that the temporal poles had to be reconstructed, as well as the rostral bec, and that there are no Broca’s cap regions available for study, given the damage to the sphenoid bones on both sides.

Volume and Method The volume as ascertained by Tobias (1963) is 530 ml. We believe that the size is closer to 520 to 525 ml, given the slight enlargement of the length of the temporal lobe in their reconstruction (Holloway, 1972: Fig. 8:184). The reliability is A1. Recently Falk et al. (2000) suggested the endocranial volume to be 500 ml, based on water displacement of a hemi-endocast multiplied by two. It is probable that any error in the determination rests upon the temporal pole reconstruction. Without further description we regard the volume of 520 to 525 ml as more accurate, since there can be a potential problem in choosing a true midsagittal plane. The Human Fossil Record, Volume 3, by Ralph L. Holloway, Douglas C. Broadfield, and Michael S. Yuan. C 2004 John Wiley & Sons, Inc. ISBN 0-471-41823-4 Copyright


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feature that appears common to robust australopithecines. The middle meningeal vessels are clearly emanating from the foramen spinosum on the inferior temporal lobes, bifurcating into anterior and posterior moieties. The anterior branch is lost due to the missing sphenoidal part of the cranium.

Morphometric Data The left chord length between frontal and occipital poles is 128 mm; the right side is 131 mm, but that includes a small excrescence from the patent lambdoid suture. The left lateral arc length is 160 mm; the right is ca. 170 mm, again the difference being caused by sutural excrescences. The left dorsal arc length is ca. 170 mm; the right side is ca. 172 mm. The maximum chord breadth is 105 mm; the arc breadth over vertex is ca. 158 mm. The bregma-basion chord length is 88 mm, and the maximum height, from the lowest temporal lobes to the vertex, is ca. 88 mm. The maximum cerebellar width is ca. 84 mm, and between the sigmoid sinuses the width is ca. 93 mm. The bregmalambda chord length is 86 mm; the arc length is 95 mm. The bregma-asterion chord length (left) is ca. 94 mm; the arc is ca. 115 mm. The biasterionic width is ca. 80 mm. The bregma-deepest cerebellum is ca. 92 mm.

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Significance Discovered in 1959, this specimen provided the first real discovery of East African robust forms as a taxon different than the South African robust forms. Moreover it has been absolutely dated to about 1.75 MYA, so OH 5 positioned at this time extends by almost a million years our fossil record of early hominids and provides what South Africa could not in the way of chronometric dating from its tuffs.

References Falk D, Redmond JC, Guyer J, Conroy GC, Recheis W, Weber GW, Seidler H. 2000. Early hominid evolution: A new look at old endocasts. J Hum Evol 38:695–717. Holloway RL. 1972. New Australopithecine endocast, SK 1585, from Swartkrans, South Africa. Am J Phys Anthropol 37:173–186. Holloway RL, Yuan MS, Broadfield DC, DeGusta D, Richards GD, Silvers A, Shapiro JS, White TD. 2002. The missing Omo L338y-6 occipital marginal sinus drainage pattern: Ground sectioning, CT scanning, and the original fossil fail to show it. Anat Rec 266:249–257. Tobias PV. 1963. Cranial capacity of Zinjanthropus and other australopithecines. Nature 197:743–746.

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Figure 27. OH 5 (scale = 1 cm).

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there is a posteriorly oriented depression interpreted as the interparietal sulcus as well as angular and surpramarginal moieties of the inferior parietal lobule. Just anterior to the lambdoid suture, particularly on the left side, there is a depression that was probably caused by the inferior lip of the posterior edge of the parietal bone. One cannot rule out the possibility that it might also be (in part) the lunate sulcus. The depression, referred to as the interparietal, however, does not course that far posterior as to abut against the lambdoidal sutural region, which would signify a pongid pattern. However, a more anterior pongid placement for a lunate sulcus is not apparent on this endocast. Thus we feel confident that the lunate, if it was present on this australopithecine endocast, would have been in a more human-like posterior position (see Figs. 1, 2, and 7 from Holloway, 1981). No trace of an enlarged or small remnant of the occipital/marginal sinus is seen on this endocast (but see below for controversy). Both sigmoid sinuses were reconstructed, but both transverse sinuses are present, with flow going to the right transverse sinus from the longitudinal sinus.

OMO L338Y-6

Gross Description This is a posterior, undistorted endocast portion made from both parietal and the occipital bones (Rak and Howell, 1978). The frontal lobe, temporal lobes, and anterior cerebellar lobes, as well as the foramen magnum region, were reconstructed using plasticene (Holloway, 1981).

Volume and Method The volume is 427 ml, based on the mean of five water displacements. The reliability is suggested as A1-2.

Endocast Details There is a slight left occipital petalia, both in length and width. In Holloway’s (1981) description, he identified a limb of the precentral gyrus on the left side, a possible small and posterior extension of the Slyvian fissure, but this is very dubious. On the left side there is a superior genu or limb of the postcentral gyrus, and the broken margin of the parietal would fall roughly coincident with the central sulcus. Also identified on the left side

Morphometric Data The chord length from frontal to occipital poles is 116 mm, the lateral arc is 154 mm, and the dorsal arc is 160 mm. The maximum chord breadth is 91 mm; the dorsal arc breadth over the vertex is 135 mm. The bregma to basion chord length is 86 mm, and the depth from lowest temporal lobe to vertex is 78 mm (see Holloway 1981, p. 117, for other measurements

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and indexes). The biasterionic breadth is ca. 70 mm; the bregma-asterion (rt) chord is ca. 87 mm, and the arc ca. 103 mm. The maximum cerebellar width is ca. 78 mm.

Significance This cranium was described and assigned to the Australopithecus boisei taxon by Rak and Howell (1978). Holloway’s (1981) study suggested that it was more likely that the specimen should be assigned to Australopithecus africanus, or as in Holloway (1988), Australopithecus aethiopicus. The reasons cited were the combination of small cranial capacity (427 ml), rounded cerebellar lobes, and the lack of any occipital/marginal sinus. Holloway (1988) pointed out that he could have been wrong and that indeed the specimen could most likely be P. boisei, but that the details could not definitively prove exactly which taxon the specimen belonged to. White and Falk (1999) claimed to have found an occipital/marginal sinus, and their observations of the cerebellum convinced them that this specimen should be assigned to P. boisei. Holloway et al. (2002) showed that the original specimen did not have an enlarged occipital/marginal sinus, thus the lack of this feature leaves

the taxonomic status of the specimen momentarily unresolved.

References Holloway RL. 1981. The endocast of the Omo juvenile L338y-6 hominid specimen. Am J Phys Anthropol 54: 109–118. Holloway RL. 1988. “Robust” Australopithecine brain endocasts: Some preliminary observations. In: Grine F, ed, The Evolutionary History of the “Robust” Australopithecines. New York: Aldine de Gruyter, pp 97–106. Holloway RL, Yuan MS, Broadfield DC, DeGusta D, Richards GD, Silver A, Shapiro JS, White TD. 2002. Missing Omo L338y-6 occipital-marginal sinus drainage pattern: Ground sectioning, computer tomography scanning, and the original fossil fail to show it. Anat Rec 266: 249–257. Rak Y, Howell FC. 1978. Cranium of a juvenile Australopithecus boisei from the lower Omo Basin, Ethiopia. Am J Phys Anthropol 48:345–366. White DD, Falk D. 1999. A quantitative and qualitative reanalysis of the endocast from the juvenile Paranthropus specimen L338y-6 from Omo, Ethiopia. Am J Phys Anthropol 110: 399–406.

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Figure 28. Omo L338y-6 (scale = 1 cm).

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Sts 19/58

STS 5 MORPH

This specimen was described as “skull VIII” in the Broom and Schepers (1950) monograph. It consists of a basal portion with a complete left temporal lobe, both cerebellar lobes, the brain stem, and foramen magnum region. It is entirely undistorted and the details are very fine. We do not have the dorsal calotte piece, which is known as Sts 58, figured by Schepers in the work cited above, and it will not be described here.

Gross Description Sts 5 This is a complete endocast, molded from the inside of two halves of travertine matrix that encased the skull, which was shattered horizontally during Broom’s 1936 work at Sterkfontein. Schepers (1946, 1950) described the endocast. We find it difficult to accept his enthusiastic depiction of various gyri and sulci. Indeed, if we may be permitted a personal opinion, this is one of ugliest brain endocasts we have seen, and we suspect that part of our judgment is due to the interior of the cranial halves having been very difficult to clear of matrix, and thus some of the original bony internal table is lost. The endocast has a huge rostral bec on the frontal lobe. The temporal lobes jut forward and rather deeply into the middle cranial fossae; the cerebellar lobes jut posteriorly, and almost surpass the occipital poles in their posterior extension, a primitive condition one might expect on pongid endocasts. The surface detail is also poor, making identification of sinuses and meningeal vessels extremely difficult. Our copy is a far cry from the beautiful and seemingly smooth depictions by Schepers (1950, Figs. 1, 2, 3).

Sts 26 This is a tiny fragment showing a complete foramen magnum, medial portions of both cerebellar lobes, a small portion of left inferior occipital lobe, and part of the right transverse sinus. The size strongly suggests that this was a small child.

Sts 60 Sts 60 is a natural endocast. It is nearly complete on the left side, except for the occipital pole and posterior cerebellar lobe, temporal pole, frontal bec, and distal brain stem with the foramen magnum. The right side retains most of the frontal lobe and a portion of the medial part of the parietal lobe. While it is basically undistorted, the anterior portion of the left temporal region appears sprung slightly laterally, and both left and right Broca’s cap regions are damaged.

Sts 71 Sts 71 was described in the Broom and Robinson 1950 monograph as “skull VII.” It is a demi-endocast of the right side. As Broom and Robinson clearly noted, the

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skull suffered considerable deformation, particularly in the occipital bone (flattened, displacing the occipital portion and cerebellar lobe anteriorly). In addition the parietal and temporal squamous portions of the skull are depressed medially, thus making it necessary to correct for the distortions. The convolutional details are weak, although a reading of Schepers’s (1950) description suggests he saw more than we have.

Stw 505 The main description of this specimen can be found in Lockwood and Tobias (1999). The brain endocast available for this specimen consists of an almost complete left side, lacking the more posterior aspects of the occipital lobe, cerebellum, and brain stem. A small portion of the right prefrontal lobe is undisturbed, as well as the medial temporal pole region. The rostral bec region is complete and undistorted. The left temporal lobe is displaced laterally by 5 to 9 mm, requiring careful reconstruction. The midfrontal dorsal region appears to have collapsed by about 10 mm relative to the posterior frontal and anterior parietal lobe, with a possible exaggerated height of the latter region at the breakage zone in the region of the coronal suture. This has had a minor impact on the preservation of the left Broca’s cap region.

Type 2 This natural endocast is composed of both frontal lobes (dorsal portions). The right is more complete than the left; part of the right parietal lobe is severely displaced anteriorly and inferiorly over parts of the frontal and temporal lobes. There is a large depressed fracture in the right anterior parietal lobe. A small portion of the left superior parietal lobe is present but also distorted. There is a small part of the right temporal lobe.

Type 3 This small, mostly posterior, portion of a natural brain endocast is of a young child, from and ending at the occipital poles. There are no inferior, or basal portions a level beginning approximately posterior to Bregma. The left parietal lobe is displaced posteriorly, as are parts of the anterior parietal lobes at the anterior margins of the endocast. The lambdoid and sagittal sutures are patent.

Volume and Method

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endocranial volume, originally given as 480 ml by Broom and Schepers (1946), and 485 ml by Holloway (1970, 1973, 1981). The method is by water displacement, and the reliability is A1.

Sts 19/58 A volume of 436 ml was estimated using the partial endocast method in which the similar portions of Sts 5, SK 1585, and OH 5 were used as templates to determine percentages of the total. We regard the reliability as B1.

Sts 26 It is not possible to estimate a volume with this small fragment. It is smaller than that for Sts 19/58 or Sts 60, and we would judge the specimen to be somewhat less than 400 ml.

Sts 60 Holloway (1975) made a reconstruction of this endocast, completing the missing portions with plasticene on the left side, and measuring the volume of the hemiendocast by water displacement technique. The volume was 428 ml (2 × 214 ml), and the reliability given as A1. Falk et al. (2000) suggested that some of the Pliocene hominid brain endocast volumes could have been inflated and so prompted a re-analysis of several of the volumes. Indeed, we found that a full endocast reconstruction of Sts 60 does provide a lower estimate at roughly 400 ml.

Sts 71 A volume of 428 ml was determined on a plaster endocast that corrected for the distortions by (1) elongating the occipital/cerebellar region posteriorly and (2) building out the right lateral parietal and temporal surface that was collapsed in the original. We estimate the reliability as C1-2 (instead of 2-3), which makes our estimate of 428 ml more reliable than before. This was recently confiremed by Conroy et al. (2000) who provide a correction to previous claim by Conroy et al. (1998a), that the volume was only 375 ml, based on their failure to take the significance of the distortions into account as had Holloway (1973).

Sts 5

Stw 505

Despite the preceding judgments, the endocast is complete, relatively undistorted, and provides an accurate

We have not completed our reconstruction yet, but on the basis of rough comparisons with other endocasts

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belonging to robust and gracile forms of this time period, we note the following: the frontal lobe is clearly less pointed and wider than on either OH 5, SK 1585, or the Konso endocast, and the anterior-posterior dimensions are significantly greater than Sts 5, as is the temporal/cerebellar cleft region. (See, in particular, Lockwood and Tobias, 1999, for external cranial measurements.) We estimate a volume of between 530 and 580 ml. This estimate is clearly larger than the 515 ml estimate of Conroy et al. (1998a, b) based on water displacement, which does take into account the distortion and displacement of all of the cranial bones. While Lockwood and Tobias (1999) question aspects of the Conroy et al. (1998a, 2000) volume estimation, they do not provide an alternative value. Hawks and Wolpoff (1999) have suggested a cranial capacity between 586 and 598 ml based on different regression approaches using osteometric data from other fossils. We believe between 550 and 560 ml to be the correct volume.

Type 2 The original estimate by Schepers (1946) was 510 to 580 ml, using a mean value of 560 ml in his Table 1. This was later reduced to 520 to 540 ml in his 1950 study. MSY’s reconstruction provides a volume of 457 ml by water displacement method. Reliability is C2, given the extensive distortion, realignment of frontal, parietal and temporal portions, and addition of plasticene for the entire basal portion. This reconstruction was compared to both Sts 5 and Sts 60. The frontals are slightly smaller than Sts 5 but slightly larger than Sts 60. We believe our estimate of 457 ml is a good approximation.

Type 3 MSY has reconstructed an endocast based on carving a plaster replica of the displaced margins and re-aligning them without distortion. The remainder of the endocast has been reconstructed in plasticene, following the contours available from the original portions. The volume of the reconstructed endocast is 286 ml. We can only suggest that if Type 3 were following a human growth pattern, the volume would be approximately that of a three-year old modern human child. If we take 450 ml as an average for the gracile morphs at Sterkfontein, 286 ml would represent 63.6% of the adult volume. At this point in our research, it is not possible to be more definite regarding the expected adult endocranial volume.

Endocast Details Sts 5 There is a distinct asymmetry in the Broca’s cap region, with the left region being discernibly larger than the right. The asymmetry could be due to some distortion or fault during the cleaning process, though this is highly unlikely. There is a small left occipital petalia that is not simply due to the crack line running through the occipital poles, and the region is also wider on the left side. There does appear to be a right frontal petalia, but this is difficult to separate from the mild distortion in that region. These petalias and larger left Broca’s cap region are concordant with probable right-handedness. There are small traces of orbital sulci, and we agree with Schepers’s (1946) illustrations showing the pituitary, eminence of the Gasserion ganglion (trigeminal nerve root), middle meningeal vessel, a bit of auditory nerve, and a small bit of the hypoglossal nerve. However, we do not see the carotid canal (foramen lacerum) as clearly as Schepers indicates.

Sts 19/58 Both middle and inferior temporal sulci can be seen. The left temporal pole region bears the imprints of the foramen spinosum, foramen ovale, foramen rotundum, and a small eminence leading into the superior orbital fissure just superior to foramen rotundum. Moving posteriorly, the auditory nerve is present on both sides in the temporal-cerebellar cleft, as well as the arcuate eminence. Both hypoglossal canal imprints are visible on the brain stem, superior to the foramen magnum. The sigmoid sinus is well preserved on the left side as well as the transverse sinus. It appears that the sagittal sinus gave most of its flow to the left transverse sinus, but the right sinus is missing, as well as the sagittal sinus. A tiny portion of occipital lobe on the left side is present, but not on the right side. Middle meningeal and posterior meningeal vessels issue from the left foramen spinosum.

Sts 26 The cerebellar lobes appear very small and rounded.

Sts 60 With both occipital poles missing as well as the Broca’s cap regions, we cannot assess the possible asymmetries for this specimen. The temporal lobe shows superior, middle, and inferior gyri. Just superior to the region of the left sigmoid sinus, there are two tiny sulci, probably

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related to the inferior occipital region. Since the entire posterior part of the occipital lobe is missing, it is impossible to say that there is no lunate sulcus there, as did Falk (1980). Even in pongids, such as Pan and Gorilla, the lunate sulcus seldom if ever extends to the sigmoid sinus. The left parietal lobe shows an elevated inferior arm of the precentral gyrus, and on the right side a remnant of the postcentral gyrus appears close to the midsagittal plane. The posterior part of the left parietal lobe is pitted, and there does not appear to be any trace of any angular or surpramarginal gyri, and no interparietal (IP) sulcus is evident. The frontal lobe shows considerable convolutional details, that cannot be easily described, particularly as the third inferior frontal convolution is damaged in its inferior portion. We see evidence for superior and middle frontal sulci. The prefrontal lobes are fairly rounded, and not pointed as in most pongid endocasts, suggesting that there might have been an expansion in the middle portion of the lateral aspect of the frontal lobe. On the other hand, it is not clear whether the furrow just above the flash line on the cast is an orbital frontal sulcus, and that the region below it is simply postmortem damage to the sphenoidal region of the cranium. The temporal pole is broken just anterior to the foramen spinosum, and inferior to the anterior arm of the middle meningeal vessel, which courses superiorly and posteriorly some 20 mm behind the coronal suture. The posterior division traverses the inferior edge of the temporal lobe before ascending superiorly, roughly 10 mm anterior to the sigmoid sinus. There are but few branches to either of these vessels on the dorsal endocast surface. While the cerebellar lobes are mostly missing, the anterior portion suggests that they were low and broad in form, and not rounded as in the case of Sts 5. Within the cerebellar/temporal cleft, an auditory nerve impression is visible as is the arcuate eminence. There is also a remnant of the superior petrosal sinus.

Sts 71 Few details are trustworthy, although Schepers’s (1950) account provides a detailed depiction of the frontal lobe, suggesting superior, middle, and inferior frontal sulci are identifiable. There is rather clear, but short, inferior frontal sulcus. The rostral bec is covered with matrix on our copy, and appears to have been displaced toward the right side, thus occluding the orbital surface of the frontal lobe. On the temporal lobe, part of the

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anterior portion of the middle temporal sulcus is visible. The temporal/cerebellar cleft remains filled with matrix. The sigmoid and transverse sinuses are visible, and the flow from the sagittal sinus appears to be mostly to the right side.

Stw 505 Given the incompleteness and distortions of the cranial fragments, nothing can be said of the asymmetries in cortical petalias, although the left frontal pole is more anterior and wider than the right side. The frontal is more squared off than even Sts 5, and the anterior part of the middle frontal convolution is large and protuberant. The Broca’s cap region is not as pronounced as in later specimens, such as KNM-WT 15000. The anterior occipital portion shows a welldelineated sulcus. We believe this to be the inferior and lateral portion of the lunate sulcus, which, if correct, would indicate a lunate sulcus in a more posterior position than in any pongids we have seen. The sulcus is superior to roughly the midcerebellar length, meaning it is well posterior to the remnant of the sigmoid sinus. There is no apparent interparietal sulcus showing on this specimen, and the dorsal aspect of the occipital lobe is missing. The distance between the reconstructed midline and the lateral edge of the purported lunate sulcus is about 20 mm, a value much smaller than any chimpanzee of comparable size. There is fair detail on the parietal lobe, suggesting an enlarged inferior parietal lobule and a posterior temporal lobe. The inferior temporal lobe shows a clear inferior temporal gyrus. (See Holloway et al 2004 for further details.) There is no apparent transverse sinus, and the sigmoid sinus is extremely small. The meningeal patterns are small, and severely interrupted by the lateral temporal lobe displacement.

Type 2 Compared to the Taung child and Sts 60, this endocast shows the best convolutional details of all of the natural endocasts discovered so far. Schepers’s (1946) descriptions appear, for the most part, to be valid, and we refer the readers to his Figures 5, 9, and 13. However, Schepers’s (1946, Fig. 19) use of the Type 2 endocast to draw a map of Brodmann’s cytoarchitectonic areas for this group (described at the time as Plesianthropus transvaalensis) is daring. The superior and middle frontal gyri are present. We do not find the sulcus numbered 14 (Schepers,

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1946), to be truly the central sulcus (fissure of Rolando) but more likely the precentral sulcus, as it is located well anterior to the where the coronal suture would have appeared except for the distortion in that area. Schepers’s designation of the precentralis inferior seems to be more contiguous with what he designated as the sulcus postcentralis. His sulcus 12, the subcentralis, could be the ascending ramus of the Sylvian fissure, whereas his sulcus fronto-orbitalis, if correct, does not appear to be of any typical pongid form. This is because the ascending ramus of the fronto-orbitalis is most likely very short on this specimen, and it is the sulcus diagonalis that is not continuous with the fronto-orbitalis. If this interpretation is correct, it does suggest a more human-like disposition of the Broca’s region homologue in South African gracile forms. Schepers’s identification of the sulcus fronto-marginalis appears correct to us, this latter sulcus delineating the inferior part of the superior frontal convolution. On the parietal lobe, Schepers identifies the parallel sulcus as a continuation of the superior temporal sulcus. However, we do not see this as evident, nor do we see any indication of a lunate sulcus (Schepers’s number18, Fig. 9). Likewise we do not see good evidence for an interparietal (IP) sulcus (Schepers’s sulcus intraparietalis). The meningeal patterns are shown by Schepers (1946, Fig. 24) to be composed of a strong posterior branch of the middle meningeal as well as an anterior branch of the same; the latter seems more extensive in his diagram than on our casts. We are unable to attach any taxonomic or probable neurological importance to these.

Type 3 Schepers (1946) shows a sulcus 18 (lunate sulcus) well posterior to the open lambdoid suture by approximately 11 to 12 mm. Indeed, there is a small depression where Schepers (op. cit.) depicts it, and it is possible that it could have been the lunate sulcus. We see no reliable evidence of the interparietal sulcus, however.

Morphometric Data Sts 5 The left chord length is 124 mm; the right is 122 mm. The left lateral arc includes an excrescence, which should be subtracted from the total of 160 mm. The right side is ca. 155 mm, and we suggest that this value be used instead of that provided for the left side. The

dorsal arc, left side, is 173 mm, and the right side is 170 mm. The maximum chord breadth is 95 mm, while the dorsal arc breadth is ca. 140 mm and includes the protruding portion. The bregma-deepest cerebellum chord is ca. 105 mm. The bregma-basion chord is 102 mm, and the maximum height over vertex to lowest temporal lobe is 88 mm. The bregma-asterion chord (rt) is ca. 101 mm, and the arc ca. 115 mm. The widest cerebellar width is 73 mm, and 82 mm between the sigmoid sinuses.

Sts 19/58 The maximum chord breadth is estimated at ca. 100 mm. This is based on the maximum breadth points being located on the superior temporal gyrus, and doubling the distance between such an estimated point of the left side to the midsagittal plane through the brain stem. The maximum cerebellar width, between the sigmoid sinuses, is estimated at 90 mm.

Sts 26 We would estimate maximum cerebellar width as between 65 and 70 mm.

Sts 60 The chord length on the early Holloway (1973) endocast is 116 mm. The lateral arc is 148 mm, and the dorsal arc is 156 mm. The maximum chord breadth is ca. 100 mm, and the arc breadth over vertex 156 mm. The bregma-basion is ca. 79 mm, and lowest temporal lobe to vertex is ca. 82 mm. The bregma-lambda chord is estimated to be ca. 61 mm; the arc is ca. 66 mm. The left bregma-asterion chord is ca. 83 mm, and the arc is ca. 102 mm. The bregma-deepest cerebellum is ca. 86 mm. The widest cerebellar breadth on the new reconstruction is ca. 80 mm; the distance between sigmoid sinuses is ca. 87 mm.

Sts 71 The following measurements are based on a reconstruction Holloway made in 1973, so these are only approximations. The chord length between frontal and occipital poles is 120 mm; the lateral arc is ca. 150 mm, and the dorsal arc ca. 150 mm. The demi-endocast reconstruction is ca. 40 to 45 mm, making maximum chord breadth ca. 80 to 90 mm and the dorsal arc breadth ca. 155 to 160 mm. The bregma-basion is estimated at 80 mm, and dorsal height to vertex from lowest temporal lobe is ca. 82 mm. The bregma-asterion chord is ca. 83 mm, and the arc ca. 100 mm. The biasterionic width

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is ca. 78 mm. The widest cerebellar width is 82 mm, with width between sigmoid sinuses ca. 88 mm.

the paleoneurology of the South African Pliocene hominids deserves further independent study.

Stw 505

Sts 19/58

All measurements are estimations only: the maximum chord length between left frontal pole and occipital pole is ca. 130 to 135 mm. The lateral arc length, is estimated at 175 mm and the dorsal arc at 200 mm. The maximum chord breadth is estimated at 110 to 115 mm and the arc breadth at 160 mm. The biasterionic breadth and widest cerebellum are not certain because of distortion.

Type 2 Because of the large amount of reconstructive work, the following measurements are only rough approximations: The chord length is ca. 120 mm, the lateral arc ca. 155 mm, and the dorsal arc is between 155 and 160 mm for the left side of the reconstruction. The maximum chord breadth is 97 mm, and the arc breadth is ca. 155 mm. The bregma-basion is ca. 85 mm, and maximum height to lowest temporal lobe is ca. 75 to 80 mm.

The major significance of this specimen is that it provides an undistorted and detailed view of the temporal lobe and the cerebellar and brain stem regions of a South African gracile form. No other skull retains such splendidly preserved details: not Taung, Sts 60, Sts 71 (“skull VII”), Stw 505, nor Sts 5. It is also important in providing another volume estimate, but it should be pointed out that other specimens must be used to make such an estimate. It is this kind of methodological process that leads to the artificially low standard deviation and coefficient of variation for the brain volume estimates of this group.

Sts 26 This sample expands the specimens for the young nonadult South African Pliocene gracile forms. It might provide useful cerebellar morphology comparisons with pongids.

Sts 60 Type 3 As presently reconstructed, we obtain the following measurements: The maximum chord length is 100 mm; the lateral arc is ca. 125 mm. The dorsal arc is ca. 140 mm. The maximum chord breadth is 83 mm, and the dorsal arc breadth is ca. 138 mm. The bregmalambdoid chord is estimated at 53 to 55 mm, and arc is between 53 and 55 mm. The biasterionic chord is estimated to be between 73 and 75 mm.

Significance Sts 5 Until the discovery of Stw 505, this was clearly the largest of the South African gracile morphs discovered. If it indeed was truly “Mrs. or Ms. Ples,” it still might be the largest female brain endocast for this group. Although we are skeptical of Schepers’s (1946) interpretation and depictions of the convolutional details, we are certain that the frontal shows reorganization differences beyond what we see in pongid frontal lobes. Given its large size, the asymmetries of the hemispheres, and in particular, Broca’s cap region on the left side, the possibilities of more extensive reorganization than simply the posteriorly oriented lunate sulcus is suggested. Clearly,

This is one of the best of the five natural brain endocasts that exist for the South African gracile forms in terms of sulcal markings, and size estimation. We believe that the volume should be less than the 428 ml reported earlier by Holloway (1973, 1975), and should be more on the order of 400 ml.

Sts 71 This specimen adds yet another reasonably accurate volume. It is a good example of some of the problems facing paleoneurologists when distortion to the original cranium is present. It is also a specimen that adds more cerebral details than Sts 5. Thus, while we believe Schepers was overenthusiastic in his convolutional depictions, parts of his descriptions are accurate. This is a specimen that we believe could benefit paleoanthropology if it is given more cleaning.

Stw 505 This is surely the male counterpart of Sts 5. It indicates that so-called South African “gracile” forms could be larger creatures than we used to think. The squarish prefrontal lobes are very different from any of the robust forms yet described. We agree with Falk et al. (2000) that the gracile forms currently assigned to Australopithecus africanus are closely related to subsequent

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Homo lineages. But the evidence for a posteriorly situated lunate sulcus is that cortical reorganization occurred in this taxon, if not before in the earlier East African gracile forms such as those from Hadar. This specimen should lay to rest the controversy as to whether or not the early hominid brain was reorganized prior to enlargement of cranial volume. It simply was. (See Holloway et al. 2004.)

Type 2 Despite its unfortunate distortion this endocast is perhaps the best natural specimen available for the interpretation of sulcal and gyral morphology of the frontal lobe of the South African gracile morphs. Despite the loss of key regions related to reorganization, we believe that the frontal region, in particular the region of Broca’s cap, shows a definite trend toward a human-like pattern. We also believe, but cannot at this time verify, that the convolutions are more numerous than those typically found on the frontal lobes of pongids, such as Pan troglodytes or Gorilla gorilla. We might say the same for Sts 60 and the Taung child, but this requires further research.

Type 3 The fragment is mostly interesting because it might provide a better understanding of immature endocranial volumes of the South African gracile morphs. It is also helpful in judging the usefulness of our reconstruction methods. Clearly, more research is needed in the area.

References Conroy G, Weber G, Seidler H, Tobias P, Kane A, Brunsden B. 1998a. Endocranial capacity in an early hominid cranium from Sterkfontein, South Africa. Science 280:1730– 1731. Conroy GC, Kane A, Seidler H, Weber G, Tobias PV. 1998b. Endocranial capacity of Stw 505 (“Mr. Ples”), a large new hominid cranium from Sterkfontein. Am J Phys Anthropo Suppl 26:69–70. Conroy GC, Weber GW, Seidler H, Tobias PV. 1999. Endocranial capacity of early hominids. Science 283:9b. Conroy GC, Falk D, Guyer J, Weber GW, Seidler H, Recheis W. 2000. Endocranial capacity in Sts 71 (Australopithe-

cus africanus) by three-dimensional computed tomography. Anat Rec 258:391–396. Falk D. 1980. A reanalysis of the South African australopithecine natural endocasts. Am J Phys Anthropol 53: 525–539. Falk D, Redmond JC, Guyer J, Conroy GC, Recheis W, Weber GW, Seidler H. 2000. Early hominid brain evolution: A new look at old endocasts. J Hum Evol 38:695– 717. Hawks J, Wolpoff MH. 1999. Endocranial capacity of early hominids. Science 283:9b (in Technical Comments). Holloway RL. 1970. New endocranial values for the australopithecines. Nature 227:199–200. Holloway RL. 1973. New endocranial values for the East African early hominids. Nature 243:97–99. Holloway RL. 1975. Early hominid endocasts: volumes, morphology, and significance. In: Tuttle R, ed, Primate Functional Morphology and Evolution. The Hague: Mouton, pp 393–416. Holloway RL. 1981. Exploring the dorsal surface of hominoid brain endocasts by stereoplotter and discriminant analysis. Philos Trans R Soc Lond B Biol Sci 292:155– 166. Holloway, RL, Clarke RJ, Tobias PV. (In Press) Posterior lunate sulcus in Australopithecus africanus: Was Dart right? C. R. Palevol 3. Lockwood CA, Tobias PV. 1999. A large male hominin cranium from Sterkfontein, South Africa, and the status of Australopithecus africanus. J Hum Evol 36:637–685. Schepers GWH. 1946. The endocranial casts of the South African ape-men. In: Broom R, Schepers GHW, eds, The South African Ape-Men: The Australopithecinae. Transvaal Museum, Pretoria, S. Africa. Transvaal Mus Mem, 2, pp 1–272. Schepers GWH. 1950. The brain casts of the recently discovered Plesianthropus skulls. In: Broom R, Robinson JT, Schepers GWH, eds, Sterkfontein Ape-man: Transvaal Museum, Pretoria, S. Africa. Plesianthropus. Transvaal Mus Mem 4. p 89–117. Yuan MS, Holloway RL. 2000. New endocast reconstr5uctions of Australopithecus africanus (type II and type III) from Sterkfontein, S. Africa. Am J Phys Anthrop Suppl 30:330. Yuan MS, Holloway RL. 2003 A new brain volume for STS60 specimen of Australopithecus africanus from Sterkfontein, S. Africa. Am J Phys Anthrop Suppl 36:229.

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Figure 29. Sts 5 (scale = 1 cm).

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Figure 30. Sts 19 (scale = 1 cm).

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Figure 31. Sts 25 (scale = 1 cm).

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Figure 32. Sts 26 (scale = 1 cm).

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Figure 33. Sts 60 (scale = 1 cm).

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Figure 34. Sts 60. Stipple drawing demonstrating the meningeal pattern (scale = 1 cm).

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Figure 35. Sts 71 (scale = 1 cm).

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Figure 36. Stw 505 (scale = 1 cm).

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Figure 37. Stw 505. Reconstruction variants based on consideration for displacement of cranial fragments (scale = 1 cm).

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Figure 37A. Stw 505. Note the very strong crescentic concave-medial orientation of the sulcus labeled as the lunate sulcus in the oblique view (A) and occipital view (B). (See also Part 1, Figure 4, page 10) (scale = 1 cm).

Figure 38. Type 2 (scale = 1 cm).

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Figure 39. Type 3 (scale = 1 cm).

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There is part of the left side of the endocast from the occipital pole and cerebellar lobe up to Bregma. The endocast is undistorted, made up of very fine-grained sediments hardened in situ by calcium carbonate solutions. The details are very well preserved. See Holloway (1972) for a full description.

SK 1585 MORPH

Gross Description SK 54 The SK 54 child’s endocast is composed of two complete, but rather distorted, parietal lobes. In addition the anterior portions of the occipital lobes are more complete on the left than the right side. The distortion was plastic, and the dorsal surface is unfortunately flattened. This endocast also clearly shows the two “leopard” puncture holes made by the lower canines, supposedly as this hominid was dragged to the beast’s feeding place, presumably in a tree.

Volume and Method SK 54 Given a Bregma-lambdoid chord of 75 ml, and a biasterionic chord length of 75 mm, these measurements suggest a volume between 450 and 475 ml based on measurements of Sts 5, SK 1585, OH 5, and Taung. The reliability is D2. The endocast portions do appear larger, however, and this is most likely due to the distortion. Without the dentition, one cannot estimate what the adult volume might have been. Judging by the opening of the sutures, this child could have another 10% of its brain growth ahead of it. This would suggest an adult brain volume of more than 500 ml.

SK 859 This small fragment of the occipital and cerebellar lobes, mostly in the midline from lambda inferiorly to lower cerebellum, is broken medially to the sigmoid sinuses, which are not present. We are grateful to Dr. Jose Braga for bringing this specimen to our attention.

SK 859 The volume of this endocast can only be roughly estimated, given such a small portion, and this must be done by comparing metrically the available measurements with the remains of other robust forms. Based on the biasterionic breadth, and the estimated maximum cerebellar width, as well as visual comparisons with Omo L338y-6 and other forms currently labeled Paranthropus, we estimate the endocranial to be between 450 and 480 ml. Reliability must be low, C2-3.

SK 1585 The SK 1585 from Swartkrans, South Africa, is a natural endocast, mostly of the right side, lacking only a small portion of the prefrontal part of the frontal lobe. The Human Fossil Record, Volume 3, by Ralph L. Holloway, Douglas C. Broadfield, and Michael S. Yuan. C 2004 John Wiley & Sons, Inc. ISBN 0-471-41823-4 Copyright


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SK 1585 The lack of distortion and a very clear sagittal suture made it possible to make an accurate full endocast with minimal plasticene addition to the right prefrontal region and to a small portion of the foramen magnum region. In addition some matrix was removed from the cerebellar/temporal lobe cleft. The hemi-endocast provided a mean volume of 265 ml by the water displacement method, which, when doubled, yields a total estimate of 530 ml. The reliability is judged as A1. More recently Falk et al. (2000) have suggested a volume of only 476 ml for this specimen, which we (Holloway et al., 2000) have questioned, as we believe the midline chosen by these workers is incorrect.

Endocast Details SK 54 The distortion does not permit any measurements of asymmetry, although the impression is that there could have been a left occipital petalia. The right occipital lobe shows a definite groove posterior to the lambdoid suture, which suggests the possibility of a lunate sulcus in a relatively posterior position. The left occipital lobe also shows a slight depression posterior to the suture. The distortion, which has essentially flattened the parietals in their posterior aspect, makes it difficult, if not impossible, to ascertain whether there is an interparietal sulcus and whether or not it reaches the lambdoid sutural zone. The lateral and inferior portions of the parietal lobes show a cluster of small convolutions that could be exaggerated by the distortion caused by plastic deformation. We prefer not to hazard any further guess at the possible sulcal morphology at this time. There are clear meningeal vessels on the lateral parietal surfaces that extend over the occipital lobes. The bifurcation pattern below the squamous suture is lost, but we suspect the bifurcation into middle and posterior branches was certainly present.

SK 859 There is a small left occipital petalia, and the left occipital pole is lower than the right, a feature also present in SK 1585. The remnant of the lambdoid suture does not “pucker” the occipital lobe as in SK 1585, and there does appear to be a small inferior occipital sulcus just superior to the lateral aspect of the right occipital pole. Roughly 10 mm posterior to the lambdoid suture are slight depressions on both sides. These could conceivably be

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lunate sulci, but there is no evidence for an interparietal sulcus abutting against them. As in all other cases there is the usual ambiguity regarding the lunate sulcus. The sinuses are very strongly marked, with a large superior sagittal sinus, clearly giving most of its flow to the left transverse sinus, which appears very slightly larger than on the right side. There is a strongly marked enlarged occipital/marginal sinus on both sides of the posterior rim of the foramen magnum region. There also appears a small subdural vessel diagonally traversing part of the left occipital pole region.

SK 1585 The left occipital lobe shows stronger posterior and lateral width than the right, thus indicating a left occipital petal pattern. Unfortunately, we cannot know about the frontal petalias. The occipital poles are also strongly asymmetrical in their orientation, the left side also being more inferiorly situated than the right. The meaning of this pattern, which is not uncommon, is unknown. The right occipital lobe shows a very strong puckered pattern, deeply grooved just anterior to the lambdoid suture, particularly in its lateral aspect. It is not possible to unequivocally state that this groove represents the lunate sulcus, but there is certainly no evidence for one in a more anterior position, and the antero-posterior disposition of small tertiary gyri do not appear to be interrupted by a lunate sulcus. There is no clear trace of the interparietal sulcus running antero-posterior that usually abuts against the lambdoidal region; thus a typical pongid pattern does not manifest itself in this specimen. Roughly 10 mm superior to the transverse sinus on the right side is a sulcus (labeled the lateral occipital or prelunate, as shown in Holloway, 1972: Fig. 2, p. 175) that often abuts against the lunate. Middle temporal and superior temporal sulci are evident on the right temporal lobe, and as a clear imprint of the squamous suture. Superior to this is the Slyvian fissure, which can be seen to extend back to the parietal lobe and curve into the outline of the surpramarginal gyrus. There is a strong elevation or arm of the precentral sulcus present just posterior to the coronal suture. The frontal lobe is difficult to interpret. Holloway (1972) suggested that there was a pars triangularis, anterior to which is a marked sulcus that could be part of either the fronto-orbital sulcus or the sulcus diagonalis. Superior and middle frontal sulci are not identifiable, and the missing prefrontal portion makes it impossible to judge the actual shape of the frontal lobe. There is a small orbital sulcus on the lateral orbital surface of the

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frontal lobe. There are two fracture sites on the frontal lobe as pointed out by Holloway (1972), one of which appears to be that of a conical point, suggesting that this hominid might have suffered a fate similar to that of SK 54. The cerebellum has a shape nearly identical to that of OH 5, and we believe it shows a modern shape that is different from any of the Pliocene gracile morphs. The details on the cerebellar lobe are distinct, including the great horizontal fissure of the cerebellum. It is almost possible to actually count some of the folia on the cerebellar lobe, which number between 6 and 10. The meningeal patterns are well preserved. The middle meningeal issues from the foramen spinosum about 8 mm distal to the posterior part of the foramen ovale. Two small anterior vessels traverse the anterior temporal lobe, the larger becoming an anterior part of the middle meningeal vessel, which parallels the coronal suture. Meningeal vessels can also be seen on the frontal lobe anterior to the coronal suture. The middle branch of the middle meningeal is strongly marked and sends out smaller branches both anteriorly and posteriorly. The posterior branch of the middle meningeal vessel is also strongly marked.

Morphometric Data SK 54 The Bregma-lambda chord is 75 mm, and the biasterionic breadth chord is also 75 mm. The bregma-lambad arc is 81 mm, but it should be remembered that the parietal bones were plastically deformed.

SK 859 We estimate maximum cerebellar width to have been ca. 80 mm, with biasterionic breadth ca. 73 mm. The interoccipital pole width is ca. 20 mm.

SK 1585 The anterior-posterior chord length from the reconstructed frontal pole to the occipital pole, right side, is 129 mm. The lateral arc is 190 mm, and the dorsal arc is 165 mm. The maximum breadth chord, on the superior temporal gyrus, is 98 mm, and the maximum arc breadth over vertex is 166 mm. The bregmabasion is ca. 93 mm, and 96 mm from bregma to

deepest cerebellar lobe. The maximum height from the deepest temporal lobe to the vertex is 86 mm. The maximum cerebellar width at the sigmoid sinus is 82 mm. The bregma-lambda chord is 81 mm, and the arc is 96 mm. The bregma-asterion chord is 92 mm, and the arc is 115 mm. The biasterionic breadth is estimated as 70 mm. Additional measurements are in Table 1 of Holloway (1972).

Significance SK 54 This is a dramatic specimen given the punctate marks, which so closely fit the average intercanine space of the leopard mandible, and the young child’s age. The convolutional pattern is tantalizing, but the distortion makes it hazardous guesswork.

SK 859 Smaller-brained robust forms were also in South Africa approximately 1.8 MYA, as this specimen is most closely comparable to KNM-ER 13750, KNM-ER 17000, and KNM-ER 23000 in overall morphology and size. The sinus pattern is also very similar. This suggests that smaller-brained robust morphs were widely distributed in Africa, at least from Ethiopia to South Africa.

SK 1585 This is so far the only natural endocast for a robust form. Because of its lack of distortion and relative completeness, this specimen presents an important set of data with regard to size and morphology. The similarities to OH 5 are very strong (see Figs. 7–8 in Holloway, 1972), and indeed the juxtaposition of the basal views helps to show why OH 5 might be somewhat smaller than the 530 ml estimate provided by Tobias (1963) as it shows a correction for the length of the temporal lobe is necessary given the missing sphenoid portions, and jutting temporal poles. The strong and complete patterns of the middle meningeal vessels are important taxonomic evidence for these vessels. The puckering of the occipital lobe in a relatively posterior position suggests that there was a lunate sulcus in a posterior position. The asymmetry of the occipital lobes, and poles, is suggestive of

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right-handedness, but without the frontal lobe, this is simply speculation.

References Falk D, Redmond JC, Guyer J, Conroy GC, Recheis W, Weber GW, Seidler H. 2000. Early hominid evolution: A new look at old endocasts. J Hum Evol 38:695–717.

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Holloway RL. 1972. New australopithecine endocast, SK 1585, from Swartkrans, South Africa. Am J Phys Anthropo 37:173–186. Holloway RL, Yuan MS, Marquez S, Broadfield DC, Mowbray K. 2000. Extreme measures of SK 1585 brain endocast: the endocranial capacities of robust australopithecines revisited. Am J Phys Anthropo Suppl 30:181–182. Tobias PV. 1963. Cranial capacity of Zinjanthropus and other australopithecines. Nature 197:743–746.

Figure 40A. SK 54 (scale = 1 cm).

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Figure 40B. SK 859 (scale = 1 cm).

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Figure 41. SK 1585 (scale = 1 cm).

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least amount of reconstruction. The problem was to ascertain the midline, or midsagittal plane, with accuracy. Since a plane is determined by three points, RLH used three needles mounted in vertical stands at the same height to find such a plane. Once found, a dimensionally accurate plaster cast was sanded down exactly to the needle-inscribed midline plane, the missing portions added with Plasticene, and the matrix removed from the cerebellar/temporal lobe cleft. The resulting volume was 202 to 205 ml, which, when doubled, provides a figure of 404 to 410 ml for the complete brain volume. At that time the age estimate was of a child roughly six years old (Dart, 1925), and by assuming the child still had some growth to achieve (8%), the adult brain size was estimated at 440 ml. This process was done on three plaster blanks, and the range of variation was quite small. It was this process and value that was published by Holloway (1970). This find was somewhat shocking1 and RLH specifically requested that the late Alun Hughes and Dr. P. V. Tobias attempt to verify or disprove this result. As we believe Tobias (1991: 532) makes clear, they concurred with Holloway’s findings. More recently Mann’s (1975) estimates of age based on dental eruption patterns has been become controversial, and some workers (Bromage, Dean, Smith, etc.) regard the pattern as being ape-like and not human,

TAUNG CHILD

Gross Description One of the five South African natural brain endocasts, the Taung find of 1924 (Dart, 1925) is composed of an almost complete cranium, mandible, and attached brain endocast, which comprises almost the entire right side, except for a small prefrontal fragment that remains in the cranial frontal portion. The endocast includes ca. 28 mm on the left side, which diminishes to the loss of a very small portion of the right midsagittal section, commencing roughly at lambda. Both the cerebellar/temporal lobe cleft and the Sylvian fissure are filled with matrix. The obverse right face of the endocast is covered with calcite crystals, and the natural brain surface is that of fine-grained brownish red sediment that reminds one of semiprecious jasper.

Volume and Method Dart (1925) had initially estimated the volume of the endocast as ca. 520 ml. When RLH worked on this specimen in 1969, he was struck with the need to obtain an accurate hemi-endocast, which would offer the

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Indeed, as Tobias (1991) points out, Zuckerman (1928) found a volume of 500 ml, and Keith (1931) got a value of 450 ml (doubled from 225 ml). In fact Holloway was not aware of Keith’s finding!

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and as a result the adult value is 3.3 years (Bromage, 1987). As for the true child’s volume of the endocast, we believe a reliability of A1 applies. We await a synthesis of the controversy before accepting a newer estimate of the adult volume, and will retain our value of 440 ml as the adult volume.

Endocast Details Despite the best efforts of several workers (Dart 1925, 1953; Schepers 1946; Keith 1931; Holloway 1970, 1973 1975, 1988; Falk 1980, 1983, 1989) the convolutional details of the Taung child’s endocast remain controversial (see Holloway, 1985, for an in-depth treatment of the matter of the lunate sulcus). Of all the natural endocasts, with the possible exception of the frontal lobe of Type 2, no other endocast specimen approaches Taung with respect to details, which on first glance appear easy to interpret. This is not the case, however. Two regions offer a surprising degree of controversy, and they are crucial to an understanding of early hominid brain evolution. These are the third inferior convolution, in particular, Broca’s cap region or homologue, and the posterior occipital portion and the presence or absence of a pongid-like lunate sulcus in that region. As to the posterior part of the endocast, Dart (1925, 1926, 1953, 1959) believed that there was a LS in a posterior position, and that it was under the lambdoid suture. As he had studied with Grafton Elliot Smith in London, the neuroanatomist who put the lunate sulcus on the map so to speak, we find it inconceivable that Dart mistook the lambdoid suture for the lunate sulcus. (Indeed, Dart (1959) made this explicit.) Keith (1931) certainly thought so, and put the lunate sulcus in a very anterior macaque/baboon-like position, some 10 to 12 mm anterior to where it would normally appear in a chimpanzee of roughly the same brain size (Holloway 1988). Falk (1985), in her re-analysis of the australopithecine endocasts also put the lunate sulcus where Keith had placed it earlier. Schepers (1946) thought that that dimple was actually the parieto-occipital fissure, which seems unlikely to us. The typical pongid pattern is that the interparietal abuts in its posterior end with the lunate sulcus. There is no indication of the interparietal sulcus in a pongid region, and certainly not in the posterior position (i.e., in the lambdoid sutural zone), although Schepers (1946) depicts one in his line

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drawings. If he is right, then the parietal lobe of the Taung child was more complex and expanded than in any of the pongids. There is a small depression lateral to the superior parietal lobe but not continuous anteriorly with a postcentral gyrus. In the pongid placement there is no crescent-like sulcal morphology that does not violate the anterior-posterior of two A-P oriented gyri. In sum, if there were to be a crescent-shaped lunate sulcus, it would have to be under the lambdoid suture, and this cannot be clearly seen. It is understandable why Le Gros Clark (1947), Tobias (1991), and Holloway (1985) have said that one cannot determine with any certainty that there is a lunate sulcus present. It is extraordinarily difficult to illustrate this conundrum, but if one has access to a good cast of the Taung specimen, one can visually sight down the lambdoid suture, holding the specimen so that the cerebellar lobe faces the viewer. By rotating cast vertically downward, one can detect a clear depression just anterior to the lambdoid suture. Alas, this is not the same as seeing a distinct lunate. We remain convinced that the most accurate way to put it is to say that there is no good evidence for a lunate sulcus in a typical anterior pongid position on the Taung child’s brain endocast. Anteriorly, the small fragment 12 mm × 16 mm matrix fragment occludes the apex of the Sylvian fissure and makes it difficult to ascertain that the curved gyrus anterior to it is a true Broca’s region homologue. The curvature suggests that one is looking at pars orbitalis (Brodmann’s area 47) in its inferior limit, but it is not clear that the limiting sulcus some 18 mm anterior to the fragment is a true orbito-frontal sulcus that is pongidlike in nature. Otherwise, the frontal lobe follows the usual higher primate pattern of superior and middle frontal gyri, separated by their respective sulci, which Schepers (1946) has drawn in his diagrams. However, we do not agree with his designations within the inferior frontal convolution, such as the fronto-orbitalis, or his postcentral sulcus, which would logically be further posterior on the endocast, well behind the coronal suture. Finally we do not accept as completely accurate Schepers’s (1946: 201) enthusiastic representation of a cytoarchitectonic map for South African gracile forms—but we do admire his courage for attempting it! The meningeal patterns have been detailed by Schepers (1946), and we do not dispute them. The posterior portion of the middle meningeal vessel is very clear, and the anterior branch much less so. Judging from the up-curved region of the transverse, the

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longitudinal sinus most likely drained to the right side. Tobias and Falk (1988) have identified a possible occipital/marginal sinus along the inferior medial boundary of the cerebellar lobe. It should be remembered that the natural endocast is broken along the medial limit of the cerebellar lobe, making identification somewhat difficult. Given the high frequency of these in robust morphs, it is an intriguing possibility that the Taung child had some robust qualities.

References

Morphometric Data

Dart RA. 1959. Adventures with the missing link. Philadelphia: The Institutes Press. Falk D. 1980. A reanalysis of the South African australopithecine natural endocasts. Am J Phys Anthropo 53:525– 539. Falk D. 1983. The Taung endocast: A reply to Holloway. Am J Phys Anthropo 60:479–490. Falk D. 1985. Apples, oranges, and the lunate sulcus. Am J Phys Anthropo 67:313–315. Falk D. 1989. Ape-like endocast of “ape-man” Taung. Am J Phys Anthropo 80:335–339. Holloway RL. 1970. Australopithecine endocast (Taung specimen, 1924): A new volume determination. Science 168:966–968. Holloway RL. 1973. New endocranial values for the East African early hominids. Nature 243:97–99. Holloway RL. 1975. Early hominid endocasts: volumes, morphology and significance for hominid evolution. In: Tuttle RH, ed, Primate Functional Morphology and Evolution. The Hague: Mouton, pp 393–415. Holloway RL. 1984. The Taung endocast and the lunate sulcus: a rejection of the hypothesis of its anterior position. Am J Phys Anthropo 64:285–287. Holloway RL. 1985. The past, present, and future significance of the lunate sulcus in early hominid evolution. In: Tobias PV, ed, Hominid Evolution: Past Present, and Future. New York: AR Liss, pp 47–62.

The chord length from occipital pole to reconstructed frontal pole is 120 mm. The lateral arc length is ca. 147 mm, and the dorsal arc length is 166 mm. The maximum chord breath is 92 mm (2 × 46 mm), and the arc breadth is ca. 152 mm. The bregma-basion length is estimated at 78 mm, and maximum height from lowest temporal to vertex is ca. 82 mm. The bregma-deepest cerebellum is ca. 92 mm. The bregma-asterion chord is ca. 89 mm, and the arc is ca. 110 mm. Based on reconstruction 1, biasterionic breadth is estimated at 68 mm. The maximum cerebellar width is ca. 70 mm, while the breadth between sigmoid sinuses is estimated at 74 mm.

Significance We believe that the Taung child’s natural endocast is one of the most important early endocasts. The matter of the posterior position of the lunate sulcus, and the possible expansion of posterior parietal association cortex, early in hominid evolution, is crucial to our understanding the dynamics associated with early hominid brain evolution. Sts 60 does not have sufficient occipital lobe present to enable us to verify independently of the Taung specimen a posterior position for the lunate sulcus. The difficulty in identifying the lunate sulcus has been noted by many researchers working in the area of paleoneurology, and only Dart and Schepers appear to have been completely certain of the lunate sulcus’ position. We admit that while the sulcus cannot be seen clearly, alternative placements in more anterior positions, such as Keith’s (1931) or Falk’s (1985), are simply erroneous because they violate the available morphology on the Taung endocast. To avoid that conundrum, they place for the sulcus in cercopithecoid position. Elsewhere Holloway has attempted the metric analysis to disaprove this contention (Holloway 1984, 1988; Holloway et al., 2001).

Bromage TG. 1987. The biological and chronological maturation of early hominids. J Hum Evol 16:257–272. Dart RA. 1925. Australopithecus africanus: The man-ape of South Africa. Nature 115:195–199. Dart RA. 1926. Taungs and its significance. Nat Hist 26:315– 327. Dart RA. 1953. The relationship of brain size and brain pattern to human status. S Afr J Med Sci 21:23–45.

Holloway RL. 1988. Some additional morphological and metrical observations on Pan brain casts and their relevance to the Taung endocast. Am J Phys Anthropol 77:27–33. Holloway RL, Broadfield DC, Yuan MS. 2001. Revisiting australopithecine visual striate cortex: newer data from chimpanzee and human brains suggest it could have been reduced during australopithecine times. In: Falk D, Gibson KR, eds, Evolutionary Anatomy of the Primate Cerebral Cortex. Cambridge: Cambridge University Press, pp 177– 186. Holloway RL, Broadfield DC, Yuan MS. 2001. The parietal lobe in early hominid evolution: Newer evidence from

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chimpanzee brains. In: Tobias PV, Raath MA, MoggiCecchi J, Doyle GA, eds, Humanity from African Naissance to Coming Millennia. Florence: Florence University Press, pp 365–371. Keith A. 1931. New discoveries relating to the antiquity of man. New York: WW Norton. Le Gros Clark WE. 1947. Observations on the anatomy of the fossil Australopithecinae. J Anat 81:300–333. Mann AE. 1975. Some Paleodemographic Aspects of the South African Australopithecines. Philadelphia: University of Pennsylvania Publications in Anthropology No. 1. Schepers GWH. 1946. The endocranial casts of the South African ape-men. In: Broom R, Schepers GHW, eds,

99 The South African Ape-Men: The Australopithecinae. Transvaal Museum, Pretoria, S. Africa. Transvaal Mus Mem, 2, pp 1–272.

Tobias PV. 1991. Olduvai Gorge, Vols 4A and 4B: The Skulls, Endocasts and Teeth of Homo habilis. Cambridge: Cambridge University Press. Tobias PV, Falk D. 1988. Evidence for a dual pattern of cranial venous sinuses on the endocranial cast of Taung (Australopithecus africanus). Am J Phys Anthropo 76:309– 312. Zuckerman S. 1928. Age-changes in the chimpanzee, with special reference to growth of brain, eruption of teeth, and estimation of age; with a note on the Taungs ape. Proc Zool Soc Lond, Pt 1:1–42.

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Figure 42. Taung child (scale = 1 cm).

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Figure 43. A: position of the lunate sulcus (LS) relative to coordinates of LS in Pan troglodytes, B: position of the lunate sulcus in Taung according to Falk (1980).

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Volume and Method

KNM-WT 17000 MORPH

KNM-WT 13750 Holloway (1988) estimated the endocranial volume as minimally 450 ml but closer to 480 ml, based on comparing arc/chord measurements with KNM-WT 17000. In addition the frontal lobe is clearly larger than KNM-WT 13750. No plasticene reconstruction has been attempted. The reliability is estimated at D1.

Gross Description KNM-WT 13750 This is an almost complete dorsal portion of an endocast. It is somewhat distorted as the right temporal lobe is displaced superiorly over the lower parietal region. The basal portions are entirely missing.

KNM-WT 17000 Walker et al. (1986) estimated the volume as 410 ml. We regard the reliability to be A1. For further description, see Holloway (1988).

KNM-WT 17000 This is an almost complete endocast, lacking the dorsal part of frontal and anterior parietal lobes, posterior cerebellar lobes, and foramen magnum region. The right Broca’s cap region is also missing. The remaining basal region is intact.

KNM-WT 17400 Holloway (1988) estimated the volume as 390 to 400 ml, based on the smaller size of the frontal portion of this specimen than that of KNM-WT 17000. Reliability is D1-2. We will use the volume of 400 ml.

KNM-WT 17400 The frontal portion is complete from frontal poles to the coronal suture on the right side, and to roughly the posterior temporal lobe on the left side. The left temporal is complete, and the right temporal pole is present. Its basal morphology is very well preserved.

Endocast Details KNM-WT 13750 There appears to be a right frontal petalia as well as a very slight left occipital petalia. The convolutional details are not reliably present, although the occipital lobes show a very decided groove just anterior to the open lambdoid suture. If that were to be a result of

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the lunate sulcus, the lunate would be in a posterior position. However, we believe that the groove is much more due to the posterior and inferior lip of the parietal bone. There is no cerebellar morphology, and the sinus patterns cannot be discerned. The dorsal height appears to be relatively low (Holloway, 1988).

KNM-WT 17000 The frontal lobe is narrow and pointed, the frontal bec portion being very similar to OH 5. The dorsal height above the cerebellar lobes is not as high as in SK 1585 or OH 5. The lateral cerebellar lobes show a lateral flare and posterior protrusion, suggesting a more primitive condition. There is a small left occipital petalia, both in terms of length and width, and also a right frontal width petalia. There are almost no discernible convolutions, particularly in the frontal and occipital lobes, so questions regarding cerebral reorganization cannot be resolved (Holloway, 1988). There does not appear to be any evidence for an enlarged marginal occipital sinus, because of the missing cerebellar region and poor cortical bone preservation in the intercerebellar and interoccipital pole regions. The right sigmoid sinus is considerably larger than the left, suggesting that the sagittal sinus flow was probably to the right side. However, the unequal sizes of these sinuses should not, in our opinion, be used to claim a probable presence of accessory occipital sinuses, such as the marginal/occipital.

KNM-WT 17400 Despite the completeness of the frontal bec portion and excellent preservation of bone, the third inferior convolution regions (Broca’s caps) do not show enough detail to determine whether there was an ape-like frontalorbital sulcus, or a shape more human-like. The left Broca’s cap region appears very slightly more laterally protrusive than the right side, but this could be due to imperfections of the internal table of bone (Holloway, 1988). The rostral portion shows a deep, but narrow bec, and a few orbital sulci can be seen laterally to the bec. There is a remnant of the optic chiasm, and good detail with respect to the foramen rotundum and foramen ovale. The foramen spinosum on the left side shows the middle meningeal vessels bifurcating into anterior and posterior branches. The fossa for the pituitary is narrow and deep.

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Morphometric Data KNM-WT 13750 The maximum chord length is 127 mm left, and 128 mm right. The left dorsal arc is 161 mm; the left is160 mm. The lateral arcs can only be estimated because of distortion and missing parts: the left lateral arc is ca. 160 mm, and the right side is also ca. 160 mm. The maximum chord breath is estimated to be ca. 100 mm. The arc breadth is estimated at 140 mm. The biasterionic breadth estimated to be ca. 75 to 78 mm. We estimate the bregma-asterion chord to be ca. 100 mm, and the arc to be ca. 108 to 110 mm.

KNM-WT 17000 Our measurements are as follows: The left chord length between frontal and occipital poles is 120 mm; the right side is 121 mm. The left lateral arc between poles is 148 mm; right side is 147 mm. The dorsal arc length is 146 mm; the left side is 146 mm. The maximum chord breadth on the superior temporal lobes is 95 mm; the arc breadth is 95 mm. The bregma-basion chord is estimated to be 87 mm, and the maximum height over vertex from the lowest temporal lobes is ca. 73 mm. The maximum width across the cerebellar lobes is 85 mm. The biasterionic breadth ca. 76 mm. The bregma-asterion chord is ca. 87 mm, and the arc is ca. 103 mm.

KNM-WT 17400 The frontal breadth between Broca’s regions is 65 mm. We estimate maximum chord breadth to be between 95 and 100 mm.

Significance KNM-WT 13750 The pointed frontal lobe, yet larger endocranial volume than KNM-WT 17000, adds to our developing knowledge regarding the variability of these early East African robust forms.

KNM-WT 17000 At 2.5 million years old (Walker et al., 1986) this is an early representative of a robust line, though the exact taxonomic placement is uncertain (i.e., between P. aethiopicus or P. robustus). Because of its relative completeness, lack of distortion, and certain endocranial volume of 410 ml, it is and will be an important

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specimen in any comparisons made within and between early hominid clades.

KNM-WT 17400 The major significance is the good detail of the prefrontal region and base, particularly the orbital surface. The small endocranial volume adds to the picture of variation in the early robust forms from East Africa.

References Holloway RL. 1988. “Robust” australopithecine brain endocasts: some preliminary observations. In: Grine FE, ed, Evolutionary History of the “Robust” Australopithecines. New York: Aldine de Druyter, pp 97–105. Walker A, Leakey RE, Harris JM, Brown FH. 1986. 2.5-Myr Australopithecus boisei from west of Lake Turkana, Kenya. Nature 322:517–522.

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Figure 44. KNM-WT 13750 (scale = 1 cm).

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Figure 45. KNM-WT 17000 (scale = 1 cm).

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Figure 46. KNM-WT 17400 (scale = 1 cm).

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Bodo

Gross Description

Endocast Details

Our cast is a partial endocast of a highly distorted frontal portion, with anterior and dorsal portions of the right parietal lobe, most of the left temporal lobe, and a small portion of the right temporal pole. There is a small portion of the anterior part of the brain stem. The right frontal and temporal pole is rotated anteriorly relative to the left side, causing an anterior displacement of the right temporal pole of ca. 10 to 15 mm. There is considerable anatomical detail on the basal surface of the orbital part of the frontal lobe, an intact rostral bec, optic chiasma, pituitary depression, and foramina of the middle cranial cavity.

The frontal lobes are slightly damaged at the apex of the Sylvian fissure, making it difficult to accurately assess the possible degree of asymmetry between left and right Broca’s regions. The similarity to the Kabwe frontal lobes is very striking, there being the same kind of unusual frontal torus just anterior to the left pars triangularis region of Broca’s cap, which extends for ca. 30 mm in an anterior-posterior orientation. The feature appears less distinct or large on the right side. The Broca’s cap regions are large, with strong lateral protrusion. We judge the right frontal as wider, also corroborated by the thicker right frontal pole region. Without the occipital region, however, nothing further can be said regarding asymmetries, handedness, and cognitive functioning.

Volume and Method Our reconstruction retains the distortion described above, and consists of a complete reconstruction for the remaining right temporal lobe, parietal, occipital, and cerebellar lobes, as well as a foramen magnum region. RLH used the Kabwe complete endocast as a template for this reconstruction. Our reconstructions yields a volume of 1205 ml, but we believe that the CT-scanned study of Conroy et al. (2000), which can correct for the obvious distortion, can provide a more accurate volume at 1250 ml (they suggest a range of 1200 to 1325 ml, which is very large). We would rate the reliability as A2, given the distortion and the missing portions.

Morphometric Data We believe the dimensions to be close to those provided for the Kabwe endocast. However, the distortion and incompleteness are too severe for us to attempt estimates here.

Significance The endocast and large, robust, heavy-browed cranial elements of Bodo indicate a large geographical range for this morph, currently designated as H. heidelbergensis, over a span of some 0.4 MY, if the Kabwe cranium is considered. There is something very unusual about

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the frontal morphology that requires more study. We believe that despite the robustness of the crania, this group of hominids possessed brain sizes well within the range of modern humans, and we doubt that their cognitive abilities were very different than our own. Conroy et al. (2000) claim that the EQ of Bodo was less than that of modern humans. However, it actually fall within modern human range, but on the low side (e.g., Holloway, 1980).

References Conroy GC, Weber GW, Seidler H, Recheis W, Zur Nedden D, Jara Haile M. 2000. Endocranial capacity of the Bodo cranium determined from three-dimensional computed tomography. Am J Phys Anthropo 113:111–118. Holloway RL. 1980. Within-species brain-body weight variability: A re-examination of the Danish data and other primate species. Am J Phys Anthropo 53:109–121.

Figure 47. Endocranial views (scale = 1 cm).

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Figure 48. Frontal view showing left Broca’s cap (B) (scale = 1 cm).

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Jebel Irhoud ( Jebel Ighoud)

Jebel Irhoud 2

Gross Description

We have not fully completed a reconstruction of this endocast at the present time. The endocast portion of the left side is somewhat larger than that of Jebel Irhoud I, and we tentatively estimate a volume of approximately 1400 ml. This is based on a reconstruction in which plasticene is added to produce a midsagittal plane. We believe the temporary reconstruction has a reliability of A2.

Jebel Irhoud 1 This is an almost complete brain endocast, lacking the basal portion, temporal lobe poles, and most of the cerebellar lobes. There is some distortion in the right frontal lobe posterior to the coronal suture, and some minor displacement of lateral prefrontal lobe on the left side.

Jebel Irhoud 2 Jebel Ihroud 2 is an endocast comprised of the left side only. It is missing the frontal orbital region, brain stem, foramen magnum region, and a small portion of the medial temporal pole. The endocast is also missing various degrees of left dorsal portions. Thus a true midsagittal plane is not available and must be reconstructed.

Endocast Details Jebel Irhoud 1 There is a small left occipital petalia in length, and width, and a right frontal width petalia. The left Broca’s cap region is dramatically larger than the right, projecting more laterally and inferiorly. There is a large postcentral sulcal raised arm on both left and right sides of the anterior parietal lobe. The occipital lobes show crescent-shaped grooves posterior to the lambdoid suture that could feasibly be the dorsal limits of the lunate sulci, which indicates that the occipital lobes are of an essentially modern human pattern. The interparietal or other parietal lobe sulci and gyri cannot be seen. There is a strongly marked right transverse sinus receiving the flow from the sagittal sinus. The meningeal patterns are not extensive, and the bifurcation between anterior and middle branches of the middle meningeal

Volume and Method Jebel Irhoud 1 Holloway (1981) found a volume of 1305 ml, based on a fully reconstructed endocast, using the water displacement method. Previously Anthony (1966) and Ennouchi (1962) had suggested a volume of 1480 ml. We believe the 1305 ml is the more accurate estimate, with a reliability of A1. The Human Fossil Record, Volume 3, by Ralph L. Holloway, Douglas C. Broadfield, and Michael S. Yuan. C 2004 John Wiley & Sons, Inc. ISBN 0-471-41823-4 Copyright


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vessels can be seen on the upper temporal lobe portion within the Slyvian fissure apex.

Jebel Irhoud 2 Nothing can be said about the asymmetries of this endocast, but the left Broca’s cap region, while smaller than that of Jebel Irhoud I, is still laterally protrusive but missing the orbital (Brodmann’s area 47) portion. The prefrontal lobe shows good convolutional detail. The occipital lobe shows a definite constriction and groove just superior to the transverse sinus that could certainly be the lateral aspect of the lunate sulcus. The occipital lobe shows a small amount of bunning. The lambdoid suture is not visible, but we are confident that the groove is not caused by it. There is an angular gyrus present, but the remainder of the parietal lobes shows very little detail. The temporal pole region shows a small groove representing the middle temporal sulcus. There are extensive meningeal vessels, and they follow the pattern described on Jebel Irhoud 1.

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Jebel Irhoud 2 The maximum chord length, left side, is 182 mm. The lateral arc length is ca. 233 mm, and the dorsal arc is ca. 148 mm. Since part of the midsagittal plane on the left side appears to be missing, we will not hazard estimates of breadths and other measurements requiring an accurate midline.

Significance Jebel Irhoud 1 This is an important North African (Moroccan) representative of the later Pleistocene group, currently assigned by some to Homo neanderthalensis but by others to H. heidelbergensis. The asymmetries are within those found for modern humans, and we draw particular attention to the large left Broca’s cap, and the rounded prefrontal lobe margins. At the same time this endocast retains the classic low and broad shape pattern associated with the Middle Paleolithic morphs of Europe.

Jebel Irhoud 2

Morphometric Data Jebel Irhoud 1 The maximum chord length between frontal and occipital poles is 173 mm for the left and 173 mm for the right side. The left lateral arc length is 221 mm; the right side is 221 mm. The dorsal arc length, left side, is 130 mm; the right side is 134 mm. The maximum chord breadth is 141 mm; the arc breadth is 215 mm. The bregma-basion length is ca. 114 mm, and the maximum height from lowest temporal lobe to vertex is 109 mm. The bregma-lambda chord is 110 mm, and the arc is 115 mm. The biasterionic breadth chord is 98 mm, and the lateral arc is 112 mm. The left bregma-asterion chord is 124 mm; the right is 123 mm. The left bregmaasterion arc is 150 mm; the right is 152 mm. The maximum cerebellar width is 110 mm.

This endocast is basically similar to, but slightly larger than, Jebel Irhoud 1. The prefrontal lobe is fully modern in its appearance.

References Anthony J. 1966. Premieres observations sur de moulage endocranien des Hommes fossiles du Jebel Ihroud (Maroc.). CR Acad Sci[D] (Paris) 262:556–558. Ennouchi E. 1962. Un neanderthalien: L’homme du Jebel Ihroud (Maroc.). Anthropologie (Paris) 66:279–299. Holloway RL. 1981. Volumetric and asymmetry determinations on recent hominid endocasts: Spy I and II, Djebel Ihroud I, and the Sale Homo erectus specimens, with some notes on Neanderthal brain size. Am J Phys Anthropo 55:385–393.

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Figure 49. Jebel Irhoud 1 (scale = 1 cm).

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Figure 50. Jebel Irhoud 1. Stipple drawing demonstrating the meningeal pattern (scale = 1 cm).

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Figure 51. Jebel Irhoud 2 (scale = 1 cm).

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Figure 52. Jebel Irhoud 2. Stipple drawing demonstrating the meningeal pattern (scale = 1 cm).

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Kabwe

Gross Description

appears to have an unusual torus-like protrusion in this region. We are not sure whether this could be explained as part of the infection this individual had, which ravaged its dentition, mastoid processes, and part of the temporal bone. Smith (1928) was convinced that the furrow anterior to the lambdoid suture was indeed the lunate sulcus. There is a smaller furrow roughly 5 mm posterior to the suture, which we believe could also be a possible location for the lunate sulcus. Certainly the left complete occipital lobe shows considerable sulcal complexity in its inferior and lateral aspect that appears at odds with the idea of a primitive retained condition of primary visual striate cortex. We also wonder to what degree the very large right transverse sinus, which receives most of the confluens flow, might have modified the external shape of the occipital lobe. The right inferior parietal lobule shows more tertiary convolutional detail than on the rest of the endocast. The meningeal vessels are strongly marked on this endocast, and in particular, over both Broca regions, whose origins are lost within the Sylvian fissure’s apex. The middle meningeal vessel is thick, coming out of the foramen spinosum and sending small branches along the inferior temporal lobe. The middle branch of the middle meningeal vessel is thick and ascends along, but somewhat posterior to, the coronal suture.

The Kabwe brain endocast is nearly complete, missing only a small section of right occipital and parietal lobe. The preservation of the internal table of bone was excellent, and the brain endocast surface shows considerable sulcal and meningeal detail.

Volume and Method A volume of 1280 ml was given by Smith (1928), while Pycraft (1928) mentioned that Keith found a volume of 1300 ml. The methods for these volumes were not discussed by Smith or Pycraft. We agree with the latter volume based on our own reconstruction of the endocast, and volume determination by water displacement. The reliability is A1.

Endocast Details The brain endocast is long, low, and broad, reminiscent of Neanderthal. Depending on the orientation of the endocast, one can see a left occipital petalia when rotating the frontal pole upward, but a right petalia when orienting the frontal lobe inferiorly. The lateral part of the right occipital lobe is missing, but despite this, the width of the right lobe appears wider. The frontal lobe widths appear equal. However, the left Broca’s region is more protuberant and larger than the right side, which

Morphometric Data

The Human Fossil Record, Volume 3, by Ralph L. Holloway, Douglas C. Broadfield, and Michael S. Yuan. C 2004 John Wiley & Sons, Inc. ISBN 0-471-41823-4 Copyright


All of the following measurements are from our cast and reconstruction. The maximum chord length, left side,

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is 174 mm; the right side is 176 mm. The lateral arc length, left side, is 223 mm; the right side is 221 mm. The left dorsal arc length is 225 mm; the right side is 232 mm. The maximum chord breadth, on the superior temporal lobes, is 139 mm; the arc breadth over the vertex is 225 mm. The bregma-basion chord is ca. 124 mm, and the maximum height from lowest temporal lobe to vertex is ca. 110 mm. The bregma-lambda chord length is 104 mm; the arc length is 110 mm. The left bregma-asterion chord length is 121 mm; the arc length is 146 mm. The right side cannot be measured. The biasterionic chord width is ca. 113 mm, the arc length over the transverse sinus is ca. 130 mm, and the dorsal arc is ca. 160 to 165 mm. The maximum cerebellar width is estimated to be 115 to 120 mm.

Significance The endocranial volume is well within the range of modern humans, and the frontal lobe morphology is advanced. The very large brow ridges, rounded and protruding occipital lobes, and the low, flat shape of the

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endocast are reminiscent of the features seen in fossils such as Amud or Ngandong. Smith (1928) thought that the temporal and parietal lobes simply had not evolved as far as modern humans, but we do not regard the features as necessarily primitive. The detailed morphology of the base is excellent, and given the superb state of preservation of internal table of bone, this is an important brain endocast, not just in its own right but as a comparative tool.

References Pycraft WP. 1928. Rhodesian man: Description of the skull and other human remains from Broken Hill. In: Pycraft WP, Smith GE, et al., eds, Rhodesian Man and Associated Remains. London: British Museum (Natural History), pp 1–51. Smith GE. 1928. Endocranial cast obtained from the Rhodesian skull, British Museum of Natural History. In: Pycraft WP, Smith GE, et al., eds, Rhodesian Man and Associated Remains. London: British Museum (Natural History), pp 52–58.

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Figure 53. Endocranial views (scale = 1 cm).

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Volume and Method

KNM-ER 1470 MORPH

The volume of the first reconstruction was 752 ml as done by water displacement, while the second reconstruction yielded a volume of 753 ml. Minor shape variations in sculpting the foramen magnum and brain stem portions account for this difference. The reliability of these reconstructions is A2, given the noticeable distortion that has not been corrected.

Gross Description The original endocast was made from latex rubber within the original cranial fragments (base of cranium missing), and was stabilized with plaster. The individual cranial fragments were unglued and removed from the vulcanized latex endocast. This latex mold was then cast using a silastic medium, and plaster casts were obtained from this mold. The reconstructions for volume estimates were done twice, involving only the basal portions, namely portions of left and right cerebellar lobes, brain stem and foramen magnum area, medial portions of the temporal poles, and a small portion of the rostral bec of the frontal lobe. These additions were not extensive. The original latex endocast no longer exists, having undergone extensive degradation with time. The resulting endocast is unfortunately distorted, the right side being displaced inferiorly with respect to the left side, and with a more forward thrust of the right temporal lobe (see basal and frontal views). The frontal lobe is free of noticeable distortion, as are the occipital and posterior parietal portions.

Endocast Details The endocast shows considerable asymmetry in that there is a well-defined left occipital petalia, both in the width and posterior projection, as well as a clear right frontal breadth petalia. Neither of these can be attributed to the postmortem distortion of the cranial fragments. Convolution details are not available except, interestingly, in Broca’s region, the left side being more laterally and inferiorly projecting, an asymmetry not caused by the distortion. While it is not possible to definitely identify the three parts of Broca’s region, it is clear that the pattern is distinctly Homo-like, and well advanced over either pongid or australopithecine conditions. The occipital lobes are without any unambiguous sulcal markings. The poor quality of the internal table of cranial bone makes it difficult to assess the venous drainage pattern, although there is a clear sigmoid sinus on the right side, and a recognizable remnant of the right transverse sinus, which appears to receive the most flow from the longitudinal sinus. There is no indication

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of an enlarged occipital/marginal sinus given the poor quality of the intercerebellar region with regard to internal table of bone. The cerebellar lobes are more triangular in shape than rounded as in either KNM-ER 1805 or KNMER 1813 and modern in appearance. The prefrontal lobe is rounded, and not pointed as in earlier hominids or pongids. The meningeal patterns are weakly visible and few along the dorsal and lateral aspects of the endocast. The temporal lobes show clear emission of the middle meningeal vessels from the foramen spinosum, which then branches into a small anterior branch, a larger well-defined middle meningeal, and a smaller posterior meningeal vessel.

Morphometric Data The chord length of the left side of the endocast from frontal to occipital poles is 140 mm; the right side is 138 mm. The lateral arc length, left side, is 175 mm, and the right side 173 mm; the dorsal arc length is 190 mm left, and 185 mm right. The maximum chord breadth is 115 mm, and the arc breadth over the dorsal surface between maximum breadth points is ca. 178 mm. These breadth figures include the distortion, and are only meant to be approximations because of the lateral and inferior displacement of the right temporal lobe. The bregma-basion chord length is ca. 103 mm to the reconstructed foramen magnum rim, and the height from vertex to lowest temporal lobe is ca. 104 mm, using a mean distance between the two temporal lobes, the right side being displaced inferiorly. The maximum cerebellar width is ca. 92 mm, and between sigmoid sinuses ca. 96 mm. The right bregma-asterion chord is ca. 110 mm; the arc is ca. 125 mm. The bregma-deepest cerebellum is ca. 110 mm. The bregma-lambda chord is ca. 91 mm, and the arc ca. 100 mm.

Significance The currently accepted date of 1.8 MYA provides the earliest large-brained representative of Homo with a morphologically modern-frontal lobe appearance. Indeed, among us, RLH made it very clear to Richard Leakey that the left Broca’s region was more human in appearance, which Leakey described in two of his books (Leakey and Lewin, 1978, 1992). This mean modern appearance was affirmed by Falk (1983) but she did not acknowledge Holloway’s earlier finding in her paper.

The clear-cut (despite distortions) left occipitalright frontal petalial pattern is strongly concordant with the premise of right-handedness in this fossil hominid. This concordance finds a fascinating agreement with the work of Toth (1985), which claims that some of the stone tools show a right-handed manufacturing process. Thus, while the question of occipital lobe morphology involving a posterior human-like placement of a lunate sulcus or posteriorly situated boundary of Brodmann’s area 17 (primary visual striate cortex) cannot be definitively answered, the ER 1470 endocast shows clearly that hominids of this time period had both reorganized frontal lobes and enlarged brains. The morphology of KNM-ER 1470 is not simply a larger sexually dimorphic version of the KNM-ER 1813 specimen; it suggests very strongly that at approximately 1.8 to 2.0 MYA there was diversity among early hominids. KNM-ER 1470 does show a morphological pattern justifying a specific designation different than that of the ER 1813 morph, as represented by the materials from Olduvai Gorge (OH 7, 13, 16, 24, 62). This important specimen should be more thoroughly studied, particularly by scanning methods that allow for corrections to be made of the distorted regions so that a more accurate cranial capacity can be rendered.

KNM-ER 1813 MORPH

Gross Description KNM-ER 1813 The endocranial cast was reconstructed from a silastic mold of the cranial interior, yielding a complete and undistorted dorsal surface. Missing are the right temporal pole, brain stem, and part of left cerebellar lobe, and a small portion of anterior prefrontal portion of the frontal lobe. The right Broca’s area region is reconstructed. The rostral bec, posterior to the beginning of the cribriform region required minimal reconstruction.

KNM-ER 1805 The endocranial cast was reconstructed upon the original silastic mold, stabilized with plaster, yielding a very complete and undistorted endocast of the entire dorsal surface, temporal lobes, and anterior rostral bec. A small amount of plasticene reconstruction was

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required to complete the prefrontal contour, just superior to the frontal bec. The right cerebellar lobe and the medial portion of the left cerebellar lobe, as well as the region of the foramen magnum, required minimal reconstruction.

Volume and Method KNM-ER 1813 Volume is 509 ml (cc) as measured by water displacement after reconstruction. The reliability is A1.

KNM-ER 1805 The volume as measured through water displacement on the reconstructed whole was 582 ml. The reconstruction reliability is graded as A1.

Endocast Details KNM-ER 1813 Except for a minor distorted left midfrontal depression, the remaining endocast is without distortion. The endocast is basically symmetrical, with minimal, if any, reliable occipital or frontal petalial asymmetries. However, there appear to be a slight right occipital petalia, as corroborated by the chord measurements shown below under 8 mm. Convolutional details are not readily apparent, except for the Slyvian fissure in its most anterior aspect. There is a slight protuberant left Broca’s region, but it is uncertain that it will be asymmetrical since the right side is missing. There are no sulcal markings that would differentiate the parts of Broca’s area, namely pars opercularis, pars triangularis, or pars orbitalis. The right sigmoid sinus is complete and fuller than the left, which is only present in its most superior aspect. The right transverse sinus is full and receives it venous drainage from the longitudinal sinus. There is a very tiny eminence along the superior medial margin of the left cerebellar lobe that is possibly a remnant of a occipital/marginal sinus. The meningeal veins are not visible on the dorsal or lateral endocast surface, as the original cranial portions was very cracked, and the internal table of bone somewhat worn. The basal portion of the left temporal lobe indicates that the middle meningeal vessels came through the foramen spinosum, sending a tripartite bifurcation posteriorly, anteriorly, and dorsally. There is not enough detail available for the meningeal pattern to be of any taxonomic significance.

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KNM-ER 1805 There are no discernible distortions on this endocast, except for a minor degree of flattening of the left frontal lobe. The endocast is very symmetrical, with a suggestion of a small left occipital petalia, both in length and breadth. There is a slight right frontal petalia, breadthwise. Convolutional details are missing, except in the temporal lobes, where the left lobe shows a discernible inferior temporal sulcus anteriorly. There is some slight gyral relief in both Broca’s regions, but not well enough defined to identify parts of Broca’s region. The remaining frontal lobe, parietal lobes, and occipital lobes are devoid of identifiable convolutional detail. The damage to the frontal lobe of the cranium does not make it possible to clearly identify an inferior orbital sulcus. Both sigmoid sinuses are visible, the left appearing somewhat larger than the right, and both transverse sinuses are visible, with drainage from the longitudinal sinus mainly from the right side. There is no indication of a occipital/marginal sinus. The internal table of bone remained intact and provides some relief of the meningeal vessels, best seen on the right side. After entering through the foramen spinosum, the middle meningeal vessel branches into a recurved anterior division, which provides a number of meningeal vessels coursing posteriorly and dorsally over the posterior portion of the frontal lobe. An inferior/posterior division of the middle meningeal provides a small number of vessels to the lower parietal and occipital bones. There is a highly visible postbregmatic depression and flattening on the dorsal surface of the endocast, reminiscent of a similar morphology on gorilla endocasts.

Morphometric Data KNM-ER 1813 The chord length of the left side of the endocast from frontal pole to occipital is 125 mm; the right side is 126 mm. The lateral arc length, left side, is 58 mm, and right side 65 mm; the dorsal arc length is 70 mm left and 75 mm right. The maximal chord breadth is 97 mm, and the arc breadth between the maximal breadth points is 150 mm. The maximal width points fall on the superior temporal gyrus. The bregma-basion chord length is 91 mm, and the maximum height from vertex to inferior temporal lobe is 89 mm. The bregma-asterion

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chord (rt) is ca. 96 mm, and the arc ca. 114 mm. The bregma-lambda chord is ca. 75 mm, and the arc 80 mm. The bregma-deepest cerebellum is ca. 105 mm. The maximum cerebellar width is 79 mm, and 83 mm between sigmoid sinuses.

KNM-ER 1805 The chord length of the left side of the endocast from frontal to occipital poles is 134 mm; the right side is 133 mm. The lateral arc length, left side, is 167 mm, and the right side is 165 mm; the dorsal arc length is 169 mm left, and 174 mm right, reflecting a slight amount of distortion of the frontal lobes. The maximal chord breadth is 97 mm, and the arc breadth between maximum breadth points, over the dorsum of the endocast, is 170 mm. The maximal breadth points fall on the superior temporal lobe. The bregma-basion chord length is ca. 93 mm, and the maximum height from vertex to inferior temporal lobe is ca. 87 mm. The right bregma-asterion chord is ca. 104 mm, and the arc ca. 122 mm. The bregma-lambda chord is ca. 79 mm, and the arc is ca. 80 mm. (It is noted here that the lambda appears in a very high position.) The bregma-deepest cerebellum is ca. 102 mm. The maximum cerebellar width is ca. 82 mm, and between the sigmoid sinuses, ca. 86 mm.

Significance KNM-ER 1813 The major significance is the enlarged volume of 509 ml over the average values for South African gracile morphs like Sts 5, and the security of the volume determination given the lack of distortion and relative completeness of the endocast. In other publications it has been suggested that KNM-ER 1813 and KNM-ER 1470 represent a case of sexual dimorphism (Stringer, 1986; Wolpoff, 1999). To us, however, despite some vague overall similarity in shape and form, the two specimens are most likely separate species. The cerebellar lobes of ER 1813 are clearly different than in ER 1470, and 243 ml is a very large degree of sexual dimorphism indeed, beyond what one would find even in Gorilla. Furthermore, given the lack of a dentition in ER 1470, and the obvious small incisor dentition of ER 1813, the case for dimorphism is again weakened. A more likely case could be made for there being sexual dimorphism between ER 1813 and ER 1805.

KNM-ER 1805 The minimal distortion and overall symmetry of the endocast add to the reliability of the volume estimate of 582 ml. The intactness of interior table of cranial bone provides good meningeal relief, absent in other endocasts of this morph, and might be useful for taxonomic purposes where sample sizes are larger for these early hominids. The Broca’s cap regions are interesting in showing a definite lateral protrusion not seen in most pongid endocasts of Pan or Gorilla, although the damage to the cranial bone does not permit a reliable identification of the full course of the inferior frontal (IF) sulcus. Falk has suggested that ER 1805 has a pongid pattern of the IF (see Holloway, 1983), but we regard the damage to be too extensive for unambiguous identification. The lack of other sulcal morphology, particularly in the occipital and parietal regions, makes it impossible to ascertain whether or not there was a lunate sulcus in a posterior position, although there is a very slight depression well posterior of the lambdoid suture that is concordant with a more human-like position of a lunate sulcus.

KNM-ER 992 MORPH

Gross Description KNM-ER 1590 The dorsal portion of the brain endocast is very incomplete and was made from the articulation of several small bone fragments, representing cranial portions commencing superior to frontal poles and extending backward somewhat posterior to the lambdoid region and laterally to roughly midparietal levels. The internal table of bone is not well preserved, and there is some minor distortion in the frontal lobe portion. Too much of the cranium is missing to reliably effect a total reconstruction.

KNM-ER 3732 This is a very incomplete and distorted partial endocast of dorsal surface. The endocast covers the regions just posterior to the frontal orbital margin to roughly the lambdoidal region, and laterally from the left Sylvian fissure to right midparietal lobe. The left side, which

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shows a prominent Broca’s region, is collapsed medially. No temporal or occipital lobes are present. The internal table of bone, while not severely damaged, shows that there was convolutional detail, but these are impossible to interpret.

KNM-ER 3733 This is a complete and relatively undistorted brain endocast, requiring very little reconstruction, except for the foramen magnum region, and a small portion of the orbital surface of the prefrontal lobe and rostral bec.

KNM-ER 3883 This endocranial cast is made from a silastic molding compound, giving a complete and minimally distorted brain endocast. The internal table of bone is eroded, and thus most of the cerebral convolutional details are missing. Only minimal reconstruction was necessary, being on the inferior surfaces of both cerebellar lobes, and a small portion of the dorsal parietal surface mostly on the left side. The left temporal lobe appears depressed medially. The orbital margins of the prefrontal lobe and rostral bec required minimal plasticene reconstruction, as did the right Broca’s cap region.

Volume and Method KNM-ER 1590 Since the articulated fragments of these calotte fragments fit over the dorsal surface of the brain endocast of KNM-ER 1470, it is appropriate to estimate the size of this brain endocast to be somewhat larger than KNM-ER 1470. The estimate Holloway (2000) suggested was minimally 800 ml. As both KNM-ER 3733 and KNM-ER 3883 vary between 804 and 848 ml, and the size of the ER 1590 cranial fragments equal or surpass these, an estimate of between 800 and 850 ml seems reasonable for this dorsal portion. The reliability, however, while based on actual fragments, must be reckoned as low (A3).

KNM-ER 3732 In Holloway (2000) an estimate of 600 to 650 ml is given. Reconstructive work is still ongoing with this specimen, but we believe the previous estimate to be too low. The dorsal undistorted curvature, and the lateral curvature, once correcting for the collapsed inferior frontal and parietal area, suggest a gross size more

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comparable to either KNM-ER 1470 or KNM-ER 3883. We would currently estimate this volume as ca. 750 to 800 ml. The reliability is low, being A3.

KNM-ER 3733 The volume of the complete brain endocast as determined by water displacement method is 848 ml (Holloway, 1983). Reliability is A1.

KNM-ER 3883 The reconstructed endocast measured 804 ml by the water displacement method (Holloway, 1983). Reliability is A1.

Endocast Details KNM-ER 1590 Given the incompleteness of this specimen and poor quality of internal bony table, no convolution details are seen. One cannot assess the asymmetry of the cerebral hemispheres, either.

KNM-ER 3732 Given the incompleteness and cranial fractures, it is not possible to ascertain asymmetries or petalia patterns. The left Broca’s region is well developed and protuberant, but the remaining prefrontal portions are missing, as is the Sylvian fissure and temporal lobe of the left side. Roughly 10 mm posterior to the Broca’s region there is visible trace of the anterior part of the middle meningeal vessel. The remaining dorsal surface does not show any other details, except for the longitudinal sinus, which thickens as it approaches the lambdoidal region. The frontal lobe appears more pointed than expected, but this could very well be due to distortion and incompleteness of the specimen.

KNM-ER 3733 Although the endocast is complete and undistorted, there had been severe erosion of the internal table of bone, thus rendering most convolutional details as unreliable. There is a definite left occipital petalia, both posteriorly and in width, but the right and left frontal breadths appear equal, with the right frontal width perhaps only very slightly wider. The inferior portion of the left Broca’s cap region (Brodmann’s area 47) is unfortunately missing, but this region is clearly more laterally projecting than the same region on the right hemisphere. Both temporal lobes have been displaced

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somewhat laterally, and the temporal poles jut strongly forward and medially. The occipital lobes are rounded and not pointed in shape, and there are slight depressions bounding them just posterior to the lambdoid suture. However, it cannot be claimed that these depressions represent a remnant of the lunate sulcus. The shapes of the cerebellar lobes are flat and rounded, unlike those of KNM-ER 1470, lending credence to the view that this specimen is indeed a different taxon. Both sigmoid sinuses are present but abraded, and the transverse sinus appears bilaterally, the right receiving the major flow from the longitudinal sinus. There is no reliable evidence for an enlarged occipital/marginal sinus. Given the erosion of the internal table of cranial bone, meningeal vessels are not reliably visible of the dorsal surface. From the foramen spinosum, there are strong middle meningeal vessels that bifurcate into middle and posterior branches, the latter coursing along the inferior margins of the temporal lobes. There is too much erosion for these vessels to be of any taxonomic significance.

KNM-ER 3883 This endocast is quite similar to that of KNM-ER 3733. The internal table of bone is damaged, making identification of cerebral convolutions impossible. There is a definite left occipital petalia both posteriorly and in width associated with a strong right frontal width petalia, thus suggesting right-handedness. The Broca’s cap regions have suffered bone erosion, but the lateral projection of the left side appears slightly larger than the right side. The prefrontal lobes are rounded along their margins, but the frontal lobe does appear flattened more so than in KNM-ER 3733. The left temporal lobe has been slightly sprung in a lateral direction, particularly along what would be the superior temporal gyrus. The right temporal lobe has been compressed in a medial direction. The base of the endocast provides interesting details seldom seen in a fossil hominid endocast. For example, the optic chiasma is present, and also a part of the hypophyseal eminence. The cranial nerves of the internal auditory and hypoglossal are clearly visible. Sigmoid and transverse sinuses are not readily visible given the bony deterioration, the left sigmoid sinus being the most visible. Flow from the longitudinal sinus appears to be to the right transverse sinus. There is no evidence for an enlarged occipital/marginal sinus. Given the bony erosion, the meningeal pattern is sparse,

and the bifurcation pattern is the same as on KNM-ER 3733.

Morphometric Data KNM-ER 1590 We estimate the overall length as ca. 165 mm, and the breadth, most likely situated over superior portions of the temporal lobes, as ca. 120 mm. These are chord measures only.

KNM-ER 3732 All the following measurements are only approximations pending further reconstruction: overall chord length is estimated roughly 140 mm, and maximum breadth at 110 mm.

KNM-ER 3733 The chord length of the left side of the endocast from frontal to occipital poles is 146 mm; the right side is 144 mm. The lateral arc length, left side, is ca. 192 mm (avoiding the displaced temporal lobes), the right side 194 mm; dorsal arc length is 204 mm left, and 205 mm right. Maximum chord breadth, just slightly above superior temporal gyri is 122 mm, and the arc breadth over the vertex is ca. 190 mm. The bregma-basion chord length is 117 mm, and the maximum height from lowest temporal lobe to vertex is ca. 197 mm. The bregma-asterion chord (rt) is ca. 113 mm, and the arc ca. 133 mm. The biasterionic breadth is ca. 95 mm. The bregma-lambda chord is ca. 97 mm, and the arc ca. 104 mm. The bregma-deepest cerebellum is ca. 114 mm. The maximum cerebellar width is ca. 101 mm, and 104 mm between sigmoid sinuses.

KNM-ER 3883 The chord length of the left side of the endocast from frontal to occipital poles is 152 mm; the right side is 151 mm. The lateral arc length, left side, is ca. 195 mm, and the right side 190 mm; dorsal arc length is 190 mm left, and 191 mm right. The maximum chord breadth, on the lower parietal surfaces, is 119 mm, and the arc breadth over the vertex is 184 mm. Given the compression of the temporal lobe on the left side, these breadth figures are minimal estimates, and can be slightly augmented. The bregma-basion chord length is 198 mm, and the maximum height from lowest temporal lobe to vertex is 195 mm. The bregma-asterion chord is ca. 108 mm, and the arc ca. 125 mm. The biasterionic

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breadth is ca. 97 mm. The bregma-lambda chord is ca. 76 mm, while the arc is ca. 82 mm. The bregmadeepest cerebellum is ca. 105 mm. The maximum cerebellar width is ca. 102 mm, while between the sigmoid sinuses the width is ca. 105 mm.

Significance KNM-ER 1590 The main feature of these fragments is their thickness and overall size, yielding a partial calotte endocast that can fit comfortably over the dorsal surface of KNM-ER 1470.

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have included a rudimentary language. It is doubtful, however, that the endocranial capacity or morphology can aid in deciding any taxonomic issues as to whether this specimen is assigned to Homo ergaster, Homo erectus or H. sp. indet.

KNM-ER 3883 Having two almost totally complete and relatively undistorted crania not only provides good brain volume estimates, it also allows for a greater appreciation of variation. Both in size and shape, particularly in the relative flatness of the frontal lobe, this specimen provides a contrast to the more rounded contour in KNM-ER 3733.

KNM-ER 1470 This does suggest that a middle range of endocranial capacities, well within those known for Asian specimens such as Sangiran, was developed early in Africa, between 1.8 and 2.0 MYA. The Brocals regions clearly suggest reorganization to a Homo pattern.

KNM-ER 3732 This is a truly challenging fragment that deserves more work than it has received to date. Given the largish Broca’s region, and relatively undistorted dorsal surface, it should be possible to correct for left side collapse and make minor adjustments on the right parietal crack line. If these are carefully done, a better and more reliable volume estimate could be made, as well as careful comparisons with the roughly synchronous specimens KNM-ER 1470, and KNM-ER 3373 and 3883.

KNM-ER 3733 The large volume and cerebral asymmetry, including that of Broca’s caps, suggest that certainly by 1.6 MYA, the genus Homo had advanced beyond those of earlier hominids, and that its cognitive capacities may well

References Holloway RL. 1983. Human paleontological evidence relevant to language behavior. Hum Neurobiol 2:105–114. Holloway RL. 2000. Brain. In: Delson E, Tattersall I, van Couvering J, Brooks AS, eds, Encyclopedia of Human Evolution and Prehistory, 2nd ed. New York: Garland, pp 141– 149. Leakey RE, Lewin R. 1978. People of the Lake: Mankind and Its Beginnings. Garden City, NY: Anchor Press. Leakey RE, Lewin R. 1992. Origins Reconsidered : In Search of What Makes Us Human. Boston: Little, Brown. Stringer CB. 1986. The credibility of Homo habilis. In: Wood B, Martin L, Andrews P, eds, Major Topics in Primate and Human Evolution. Cambridge: Cambridge University Press, pp 266–294. Toth N. 1985. Archaeological evidence for preferential righthandedness in the lower and middle Pleistocene, and its possible implications. J Hum Evol 14:607–614. Wolpoff M. 1999. Paleoanthropology, 2nd ed. New York: McGraw-Hill.

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Figure 54. KNM-ER 1470 (scale = 1 cm).

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Figure 55. KNM-ER 1470. Stipple drawings accenting features of the endocast (top) and the meningeal pattern (bottom) (scale = 1 cm; top image not to scale).

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Figure 56. KNM-ER 1813 (scale = 1 cm).

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Figure 57. KNM-ER 1813. Stipple drawing accenting features of the endocast (not to scale).

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Figure 58. KNM-ER 1805 (scale = 1 cm).

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Figure 59. KNM-ER 1805. Stipple drawing accenting features of the endocast (not to scale).

Figure 60. KNM-ER 1590. Dorsal view (A = anterior; scale = 1 cm).

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Figure 61. KNM-ER 3732. Upper : Dorsal view; Lower : Occipital view (scale = 1 cm).

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Figure 62. KNM-ER 3733 (scale = 1 cm).

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Figure 63. KNM-ER 3883 (scale = 1 cm).

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Nariokotome (West Turkana)

Endocast Details

KNM-WT 15000

The endocast shows a very decided left occipital petalia, both with regard to width and posterior projection, and it is also associated with a clear right frontal width petalia, suggesting that this youth was indeed most probably right-handed. The Broca’s cap on the left side is clearly larger and more protuberant than that on the right side, even allowing for bony destruction on the right side. The occipital lobes are rounded, not pointed, and asymmetrical; the left being more inferiorly situated than the right side. Both sigmoid sinuses are strongly marked, as are both transverse sinuses, the flow from the longitudinal sinus clearly going to the right for the most part. There is no indication of an enlarged occipital/marginal sinus. The smoothness of the dorsal surface is remarkable, and not a single convolution detail is present on our copy. There are no reliable meningeal markings present on the endocast we purchased, except along the lower margin of the left temporal lobe, issuing from the foramen spinosum. Begun and Walker’s (1993) descriptions and their illustrations show more details than are available on the cast we have at hand.

Gross Description We have not seen the original brain endocast reconstruction by Begun and Walker (1993), and our observations are based on a poor quality cast purchased from the National Museums of Kenya. Except for a few small missing cranial fragments, the endocast is complete and undistorted. The temporal poles are missing and have been reconstructed, incorrectly, we believe. The rostral bec is slightly displaced toward the left. The cerebellar region is complete and undistorted.

Volume and Method The endocranial volume is reported by Begun and Walker (1993) to be ca. 880 ml on the original, and to be about 908 ml if allowed for growth to full adulthood. The volume was determined by water displacement. We would estimate the reliability as X1 (A1 in terms of original endocast; we are accepting the published value), despite the inconsistent reconstruction of the temporal lobes compared with other similar endocasts such as KNM-ER 3733.

Morphometric Data The chord length of the left side of the endocast from frontal to occipital poles is 155 mm; the right side is ca. 157 mm. The lateral arc length, left side, is 190 mm, and the right side ca. 200 mm; dorsal arc length is 210 mm left and 205 mm right. The maximum chord breadth is 115 mm, and the arc breadth over the vertex is

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192 mm. The bregma-basion chord length is 118 mm, and the maximum height from lowest temporal lobe to vertex is estimated to be 105 to 110 mm. The biasterionic breadth is ca. 92 mm. The right bregma-asterionic chord is ca. 113 mm, and the arc ca. 132 mm. The bregma-deepest cerebellum is ca. 115 mm. The maximum cerebellar width is ca. 96 mm, and ca. 101 mm between sigmoid sinuses. We note that these measurements are extremely close to those obtained by Begun and Walker (1993) on the original endocast reconstruction.

cap region, this individual and his kind probably did possess some crude symbolic language abilities. This specimen is also valuable in that it allows for an accurate estimate of EQ , or encephalization quotient, for a hominid from this time period, something we have never had before. The magnificent monograph of Walker and Leakey (1993) provides many important and interesting observations relevant not only to hominid morphology but also function and behavior. We only wish that more attention had been given to the convolution details and that we had access to the original.

Significance

References

This endocast, being complete, undistorted, and associated with a complete postcranial set of remains, is a unique and invaluable occurrence. The asymmetries and clear presence of petalial patterns concordant with right-handedness suggest that the Nariokotome youth was indeed advanced beyond any early Homo stage. Given the largish and protuberant left Broca’s

Begun D, Walker AC. 1993. The endocast. In: Walker AC, Leakey RE, eds, The Nariokotome Homo erectus Skeleton. Cambridge: Harvard University Press, pp 326– 358. Walker A, Leakey R, eds. 1993. The Nariokotome Homo erectus Skeleton. Cambridge: Harvard University Press.

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Figure 64. KNM-WT 15000 (scale = 1 cm).

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Figure 65. KNM-WT 15000. Stipple drawing demonstrating the meningeal pattern (scale = 1 cm).

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consists of several bits of cranial bone floating in a sea of plaster, most without contacts with each other. Even the frontal portions, the largest elements in the reconstruction, were separated by a gap of roughly a centimeter at the narrowest juncture. The discovery and subsequent addition of a glabellar fragment to the frontal supraorbital torus appears to correct the problem of frontal lobe angulation. The impressions for the temporal lines on the frontal bones do not seem to coincide properly with more distal parietal fragments. The basal portion is entirely missing. Indeed, we do not possess a copy of the endocast reconstruction, and have only a plastic replica of the cranial fragments. Despite the missing parts, we believe that Ron Clarke and Phillip Tobias have made a fine effort in articulating the fragments in a most reasonable manner. We would be surprised if their volume estimate were far from the original in vivo value.

OH 7 MORPH

Gross Description OH 7 This is a partial endocast of the dorsal surface, based on portions of the parietal bones only.

OH 13 This partial endocast consists mostly of the right parietal and central and left portions of the occipital bone, from lambda to prosthion. Two small sphenoidal fragments permit the alignment of the foramen ovales, aiding in the reconstruction of the otherwise missing basal portion of the endocast. There is but one tiny fragment of frontal bone, but it does not help with the reconstruction of a frontal lobe as it has no contacts with other cranial fragments. Consult Tobias (1991) for a complete description of all the bony remains of this hominid specimen and his volume determination.

OH 24 This complete but very highly distorted brain endocast required reconstruction and corrections for distortion. The full description of such efforts can be found in Tobias (1991).

OH 16 The description of this find in Tobias’s (1991: 445– 449) monograph should be consulted, as we have not attempted a reconstruction of the total endocast. The reason for this was RLH’s impression that the find

Volume and Method OH 7 Originally Tobias (1964) suggested a volume of 680 ml based on a parietal tunnel partial endocast method. He found the proportions of total endocast volumes represented by the parietal tunnel, and then used that

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percentage of the whole to ascertain the total volume for OH 7. Most recently Tobias (1991) proposed an adult volume of 674 ml for this specimen, which matches very closely estimates by Holloway of roughly 687 ml (Holloway, 1973, 1975; see also Holloway 1980; Wolpoff 1981). It is difficult to do more than offer a suggestion regarding the reliability of the methods, although we believe the reliability of the volume to be quite high. We rate the reliability as B1.

OH 13 Two methods have been employed. Holloway’s (1975) reconstruction, based on a cranial reconstruction by Alan Walker, yielded a volume of 650 ml, by reconstructing the missing portions, and determining the whole by water displacement. Tobias’s (1991) method employed the partial endocast method, and provided a volume estimate of 673 ml, which replaces Tobias’s (1971) figure of 652 ml. The newer estimate also included a correction for age. We believe that these methods are not particularly accurate, so we assign values of A2 for the Holloway (1975) reconstruction and B2 for those of Tobias (1991).

OH 16 The adult volume of 638 ml was calculated by Tobias (1991: 446) using the partial endocast technique, and correcting for adult size attainment on the basis of the dentition. A value of 622 to 625 ml is estimated without the correction for its young age (Tobias 1971, 1975, 1987, 1991). We regard the reliability as B1.

OH 24 The volume of Holloway’s (1973) reconstruction was 590 ml. This volume resulted from a whole endocast reconstruction that corrected for the dorsal height being squashed into some four to five layers, and correcting the “devil’s horns” in the frontal lobe, which simply do not occur in primate brains. In addition the brainstem was cut out of the original plaster endocast and reoriented in a more posterior position. Despite the extraordinary skill and heroic efforts of Dr. Ron Clarke to extract this crushed cranium from its matrix, it remains highly distorted. Clarke’s original (see Tobias, 1991) estimate on the uncorrected endocast was 590 ml, and he expected a volume greater than 600 ml after corrections. A volume of 567 ml was found by Leakey and Walker in a personal communication with Tobias. Tobias’s (1991) most recent attempt provided a volume of 597 ml. We believe that the reliability is A2–3, given

the high degree of distortion, although that reliability of the volume estimates is very high.

Endocast Details OH 7 In his exacting monographic treatment of the brain endocasts, Tobias (1991: 536-538) identifies the following gyri and sulci: (1) posterior part of superior frontal gyrus, (2) posterior part of middle frontal gyrus, (3) precentral gyrus, (4) postcentral gyrus, (5) Sylvian (lateral) sulcus, (6) superior temporal gyrus, (7) superior temporal sulcus, (8) middle temporal gyrus, (9) inferior parietal lobule, (10) right intraparietal (interparietal, IP) sulcus, (11) middle temporal sulcus, and (12) sulcus occipitalis anterior. Plates 63 to 65, which are fine close-up photographs of the parietal tunnel, also indicate the surpramarginal gyrus. However, none of the sulcal landmarks mentioned by Tobias are illustrated, either on these photographic plates or by line drawing. We believe that one cannot truly identify frontal, temporal, or occipital landmarks based on the parietal tunnel alone. Our impression of the endocast is that while there are some occasional bumps and slight depressions, it is difficult to be so positive about the identifications of these gyri and sulci. In particular, given the flattened and crushed condition of the original parietals, we would warn that an inferior parietal lobule petalia pattern is a particularly dicey identification. We are reluctant to see the asymmetries that Tobias claims for this endocast. In any event, given the lack of both occipital and frontal portions, the key evidence for cortical reorganization is simply missing. We do not doubt that perhaps parts of expected convolutional details exist on the endocast as described by Tobias (1991), but it would have been useful if he had illustrated them. Those that he mentioned do not discriminate among pongid, hominid, and modern human.

OH 13 As described by Tobias (1991: 269–271), there are no cerebral convolutional details available that are trustworthy. Nor are there any meningeal markings on the endocranial surfaces. The superior sagittal sinus is strongly marked, as is the right transverse sinus, and the indication is that the flow was to the right side. Tobias (1991: 271) observes a right occipital petalia; with this observation we disagree. The apparent posterior protrusion of the occipital pole and lobe depends on how the

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endocast is oriented. If placed in a frontal pole–occipital pole horizontal plane, the occipital lobe protrudes further on the left side than the right, and is also wider on the left side. However, when the endocast is rotated such that the lower margins of the occipital lobes are viewed from a dorsal perspective, the picture changes, and it looks as if the right occipital lobe protrudes more posteriorly. We believe the damage to the internal table of bone in this region, plus the open area of the lambdoid suture, creates this confusion. The true occipital projections are superior to this region, and they show a wider and more projecting left side. Without confirmation of a right frontal petalia width pattern, we can suggest that given the occipital asymmetry, it is most probable that OH 13 was right-handed but the cerebral asymmetry was not as marked as in specimens such as ER 3733 and Sangiran.

OH 16 Almost no convolutional details are available, and given the fragmented nature of the endocast, it would not be prudent to make claims for petalial patterns or asymmetries. Tobias (1991) does remark upon the frontal lobes and their expanded width, which RLH pointed out earlier (Holloway, 1978). We believe we are in agreement despite Holloway’s reluctance to fully accept the reconstruction as accurate. We would hesitate to accept the identification of surpramarginal and angular gyri as Tobias asserts (p. 449). We do not disagree with Tobias’s (op. cit.) observations regarding venous drainage pattern, namely a sagittal sinus swinging into the right transverse sinus, and there being no evidence for a occipital/marginal sinus. There is no possibility of identifying lunate sulci.

OH 24 Given Tobias’s (1991) description, particularly of the frontal lobes, we must take some exception. Tobias states (p. 145): The region of the frontal lobes of the cerebral endocast is broad and appears truncated or squarish in outline, as in OH 16 . . . and KNM-ER 1470 . . . . On the endocast, a right frontal petalia is evident (Plate 13).

We disagree. The frontal lobe is highly distorted, and the “squarish” outline, which is particularly exaggerated in the middle region of the frontal lobe, is unlike any frontal morphology EVER encountered in any

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primate endocast, let alone an early hominid. We cannot be certain what its correct morphology would be; clearly, it is not similar to that of KNM-ER 1470. OH 16, as we discuss previously, is highly fragmented and not a trustworthy comparison. When Holloway (1973) made his correction, he molded the frontal lobes to approximate the condition found in South African Pliocene gracile endocasts where there was no distortion of the frontal lobe. His reconstruction also shows a right frontal petalia, but it is difficult to trust this observation fully. Given such distortion, it would be wise to view the specimens’ presence or absence of a petalial pattern as difficult to determine. There is a slight left occipital petalia, and thus a possible right would be concordant with the usual asymmetry found in hominids assigned to the Homo grade. We do not have access to the original endocast of OH 24, so we cannot comment upon Tobias’s (1991) descriptions of possible gyral and sulcal relief patterns. We believe these are difficult to discern, and will not speak to them. We agree that the meningeal patterns are not present for description. The basal portion of the endocast shows interesting detail in the temporal poles, indicating that they are fairly small, and in the hypophyseal region. A smallish rostral bec of the frontal lobe is present as well. The cerebellar lobes are considerably slung under the cerebral hemispheres, perhaps suggesting that a more accurate reconstruction could be made.

Morphometric Data OH 7 Our measurement for maximum chord breadth on the plaster cast available to us is 107 mm, and the arc measurement over vertex is 165 mm. The bregma-lambda chord is 94 mm, while the arc measurement is 99 mm. The lambda to left asterion chord length is 57 mm, the right side being 59 mm. The biasterionic breadth chord is 89 mm; the arc length over the dorsal surface is ca. 133 mm. The left bregma-asterion chord length is 103 mm, the right side is the same. The arcs are 115 and 116 mm respectively. We find that the chord length between lower ends of the frontalis margin of the coronal suture is 88 mm and that the corresponding arc is 145 mm. We offer these measurements should they be useful in multiple regression analyses. Meningeal impressions are present on both sides. There is a main frontal branch of the middle meningeal that bifurcates into an anterior and middle branch

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(Tobias, 1991). Part of the posterior meningeal branch can be seen on both sides, emerging from under the squamous suture.

fragmented remains, it is possible that this is our first good evidence for a significant increase in EQ (encephalization quotient) at about 1.9 MYA.

OH 13

OH 13

The chord length from reconstructed frontal pole to occipital poles is ca. 134 mm. The lateral arc, taken on the left side, is ca. 168 mm, and the dorsal arc, on the same side, is ca. 180 mm. The maximum chord breadth is ca. 102 mm, and the arc breadth over the vertex is ca. 170 mm. The bregma-basion chord length is estimated to be ca. 95 mm, and deepest temporal lobe to the vertex is ca. 84 to 85 mm. The maximum cerebellar width, between sigmoid sinuses, is estimated to be 82 mm.

OH 16 As we do not have an endocast available, we note the following from Tobias’s (1991: 447) Table 136: maximum length 124.5 mm; maximum biparietal breadth 105 mm.

OH 24 Keeping in mind the highly distorted nature of the endocast, the following measurements must be considered as suspect. The maximum chord length between frontal and occipital poles on the RLH reconstructed endocast is 128 to 130 mm. The lateral arc length is 160 mm, and the dorsal arc is ca. 170 mm. These are from the left side. The maximum breadth is 106 mm, on the superior temporal lobes, and the arc breadth between these points and over the vertex is 170 mm. The maximum cerebellum width is 91 mm between sigmoid sinuses. The bregma-basion is ca. 90 mm, and maximum height from lowest temporal lobes to vertex is ca. 88 mm.

Significance

The main significance of this endocranial reconstruction relates to its high cranial capacity given its cranial gracility, high cerebral height above the cerebellar lobes, and the parietal bossing (or tubers), which suggests some expansion of superior and inferior parietal lobules. The missing frontal lobes, Broca’s cap regions, and the lack of clear gyral and sulcal morphology of the occipital and parietal lobes rule out definite identification of a possible lunate sulcus. The morphology of the parietal lobes does, however, suggest that reorganization had occurred in this hominid, as does the left occipital petalia.

OH 16 Given the fragmented condition, we believe that it is a remarkable feat to have gleaned so much from this endocast reconstruction, the major significance of which is that it adds another reasonably accurate volume to this morph. Taken together (OH 7, OH 13, OH 16, and OH 24), the average volume is clearly in excess of 600 ml (641 + ml), larger than any those of the early gracile specimens currently designated within the genus Australopithecus, including the Hadar male AL 444 and the Sterkfontein Stw 505 crania. It would be wonderful if accurate estimates of body sizes could be made for these hominids to enable a trustworthy encephalization quotient to be calculated. We believe, given the small size of OH 8, and OH 62, that the EQ was welladvanced over that of the larger morphs dating prior to these finds. How much exactly would depend on accurate assessments of body weights and brain volumes for each taxon.

OH 7 This endocast is significant in several ways: (1) it provides strong evidence for an early hominid taxon, currently assigned to Homo habilis, with an enlarged brain volume beyond any of the earlier hominid groups; (2) it has been a significant battlefront, so to speak, for the airing and comparisons of different methods to ascertain the actual volume, and thus has an important methodological history; (3) the missing frontal and occipital portions, however, rule out any significant closure upon the issue of brain reorganization in this group, aside from an enlarged brain. Given the smallish postcranial

OH 24 Consonant with the affectionate designation of “Twiggy” for a once very slim human model of the 1960s, this is a small and gracile cranium, and most likely the smallest of the endocranial casts within this morph. It is thus very valuable in terms of providing a hopefully accurate volume estimate to better appreciate the variability of late Pliocene OH 7 morphs. We believe that the distorted frontal lobes into a “devil’s horns” pattern should be corrected; to leave them as uncorrected is simply neurologically nonsensical.

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OH 9 MORPH

Gross Description OH 9 This large partial, but basically undistorted endocast, is missing portions of the dorsal aspect of the vertex of the endocast, the right temporal lobe, orbital surfaces of the frontal lobe except for the rostral frontal bec, and small portions of the anterior cerebellar lobes, and brain stem.

OH 12 This partial demi-endocast is represented by a posterior cranial fragment from slightly inferior to the transverse sinus, including much of the parietal bone on the right side. Thus temporal lobe, brain stem, and frontal lobe are reconstructed from plasticene.

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apparent, although it does appear that the sagittal sinus flowed mostly to the left transverse sinus, an unusual hominid occurrence. Gyral and sulcal impressions are difficult to see, and cannot be described here. None are apparent in the occipital lobe, or the frontal Broca’s cap regions. The temporal lobe on the left side is unusual in that instead of folding medially as in most hominid and other specimens of this morph, this temporal lobe juts forward and is relatively large. Sulcal details are not apparent. In the original reconstruction by RLH, there is a small mistake regarding the depression of the orbital frontal surface, and reconstructed optic nerves and chiasma. These are too depressed and should be expanded, which will add a few more milliliters to the final endocranial volume. A posterior branch of the middle meningeal vessel is apparent on the left side, but it is a single vessel, terminated by the missing parietal portion. An anterior meningeal branch courses across the temporal lobe from the foramen spinosum and goes in an anterior direction. The left frontal bec is large, both in depth and width.

Volume and Method

OH 12

OH 9

Except for the occipital lobe, there is no convolutional detail to describe. The occipital portion shows a typical modern human pattern, although it is not clear whether the sulcus is truly a lunate sulcus or an inferior occipital sulcus. We prefer the former interpretation given its clear concave lateral portion. The lateral and inferior segments of the sulcus are very similar to those on the australopithecine Stw 505 specimen. In any event, this sulcus is in a very posterior position, well posterior to the lambdoid suture by approximately 10 mm at its least distance.

Following the contours and the present cranial morphology, the missing parts were reconstructed with plasticene to provide a total brain endocast. Tobias’s (1965) original reconstruction with A. R. Hughes had a volume of 1000 ml. Later Holloway (1975) made another reconstruction, obtaining a volume of 1067 ml, which was the average of several trials using the water displacement technique. The latter volume’s reliability is judged as A1.

OH 12 The volume was measured as 727 ml by Holloway (1978) based on water displacement of the reconstructed demi-endocast. Given that there is so much reconstruction, we regard the reliability as A2–3.

Endocast Details OH 9 There is strong left occipital petalia both in posterior and width projections. With the right side missing, we cannot be certain about a frontal petalia. There is strong asymmetry in cerebellar lobes, the left being noticeably larger and more posteriorly projecting. Both sigmoid sinuses are present, but the transverse sinuses are not

Morphometric Data OH 9 The morphometric data given here are from the plastic cast of the original endocast made in Nairobi, and the cast probably has experienced some shrinkage. Chord length, left side, is 169 mm, the left lateral arc is 208 mm, and the dorsal left arc is 220 mm. (The right side is reconstructed.) The maximum chord breadth is 130 mm, on the posterior temporal lobes, and 205 mm for the arc breadth over the vertex. The bregma-basion chord is estimated to be 112 mm, and the maximum height from lower temporal lobe to vertex is 110 mm. The biasterionic breadth is ca. 105 mm. The maximum

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cerebellar width is 110 mm and 115 mm between sigmoid sinuses.

OH 12 Given so much reconstruction, measurements are only approximate. The reconstructed endocast has a chord length of 135 mm, a lateral arc length of 175 mm, and a dorsal arc of 190 mm. The maximum breadth is estimated at 110 mm, based on the 55 mm width on the demi-endocast. We estimate the arc breadth at 180 mm. The bregma-basion can only be roughly estimated: ca. 90 mm. The biasterionic breadth is estimated at 75 mm. The maximum height from the lowest temporal lobe to the vertex is similarly an estimate: between 85 and 90 mm.

Significance OH 9 This is the largest endocast of this morph, originally assigned to H. erectus, with a volume of slightly more that 1067 ml, and well within the range of the Asian specimens often assigned to the same morph. The strong left occipital petalia suggests strong cerebral hemispheric asymmetry, and thus specializations concordant with right-handedness and other aspects of cerebral cognitive specialization. Unfortunately, the lack of Broca’s caps regions makes it difficult to speculate regarding any language behavior, but in our opinion, given the large brain volume and clear asymmetry, this taxon did possess a rudimentary language, at the least. The most striking aspect of this specimen, however, is the extremely thick cranium and the huge supraorbital torus, which has led many a student (and instructor) to speculate about their function, either in hand-to-hand combat, or as visors protecting against ultra violet (UV) radiation. . . .

OH 12 This smallish brain endocast adds to our understanding of variability, but the main significance is that the morphology of the occipital lobe is clearly reorganized to a modern human-like configuration.

References Holloway RL. 1973. New endocranial values for the East African early hominids. Nature 243:97–99. Holloway RL. 1975. Early hominid endocasts: Volumes, morphology, and significance. In: Tuttle R, ed, Primate Functional Morphology and Evolution. The Hague: Mouton, pp 393–416. Holloway RL. 1978. Problems of brain endocast interpretation and African hominid evolution. In: Jolly C, ed, Early Hominids of Africa. London: Duckworth, pp 379–401. Holloway RL. 1980. The O.H. 7 (Olduvai Gorge, Tanzania) hominid partial brain endocast revisited. Am J Phys Anthropol 53:267–274. Tobias PV. 1964. The Olduvai Bed I hominine with special reference to its cranial capacity. Nature 202:743–746. Tobias PV. 1965. New discoveries in Tanganyika: Their bearing on hominid evolution. Curr Anthropol 6:391–399. Tobias PV. 1971. The brain in hominid evolution. New York: Columbia University Press. Tobias PV. 1975. Brain evolution in the Hominoidea. In: Tuttle RH, ed, Primate Functional Morphology and Evolution. The Hague: Mouton, pp 353–392. Tobias PV. 1987. The brain of Homo habilis: A new level of organization in cerebral evolution. J Hum Evol 16:741–762. Tobias PV. 1991. Olduvai Gorge: The Skulls, Endocasts and Teeth of Homo habilis, Vol. 4. New York: Cambridge University Press. Wolpoff MH. 1981. Cranial capacity estimates for Olduvai hominid 7. Am J Phys Anthropo 56:297–304.

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Figure 66. OH 7 (scale = 1 cm).

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Figure 67. OH 13 (scale = 1 cm).

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Figure 68. OH 16 (scale = 1 cm).

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Figure 69. OH 24 (scale = 1 cm).

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Figure 70. OH 24. Tobias (1991) reconstruction (scale = 1 cm).

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Figure 71. OH 9 (scale = 1 cm).

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Figure 72. OH 12 (scale = 1 cm).

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Sale´

Gross Description

The right transverse receives most of the flow from the sagittal sinus. The meningeal patterns are described by Saban (1982) and Grimaud-Herv´e (2002).

Sal´e is an undistorted, fairly complete endocast missing only the medial aspects of the temporal poles and the orbital surface of the frontal lobes. The endocast shows the usual platycephalic shape of endocasts from Indonesia such as Sangiran.

Morphometric Details The maximum left chord length between poles is 158 mm; the right side is 157 mm. The left lateral arc length is 201 mm; the right side is 196 mm. The left dorsal arc length is 210 mm; the right side is 208 mm. The maximum chord breadth is 121 mm; the arc breadth over the vertex is ca. 190 mm. The bregma-basion chord length is ca. 110 mm; the maximum height, deepest temporal lobes to vertex is ca. 92 mm. We estimate biasterionic breadth to be ca. 92 mm; the lateral arc over the transverse sinus is ca. 115 mm, while the dorsal is ca. 145 mm. The bregmaasterion measures are similarly only approximations: the left bregma-asterion chord is ca. 105 mm; the arc length is 126 mm. On the right side, the respective measures are chord length 107 mm and the arc length ca. 133 mm. The bregma-deepest cerebellum is ca. 115 mm. The maximum cerebellar width is 95 mm, while between the sigmoid sinuses it is ca. 99 mm.

Volume and Method Jaeger (1975) claimed a volume of between 930 and 960 ml. Holloway (1981) published a volume of 880 ml based on a reconstruction of the missing parts, using water displacement methods. We regard the 880 ml volume as most accurate. The reliability is A1.

Endocast Details There is a strong left occipital petalia in length and width. There is a right frontal width petalia, suggesting right-handedness in this individual. Both right and left Broca’s cap regions are missing. The parietal lobes show considerable bossing, but we cannot make out the details of sulcal and gyral morphology. The occipital lobes are large and protruding, and the lambdoid suture nearly obliterated, and we do not see any evidence for the lunate sulcus in either an anterior or posterior position.

Significance

The Human Fossil Record, Volume 3, by Ralph L. Holloway, Douglas C. Broadfield, and Michael S. Yuan. C 2004 John Wiley & Sons, Inc. ISBN 0-471-41823-4 Copyright


This endocast demonstrates that the brain endocast phenotype of hominids similar to Sal´e, such as

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Sangiran, was indeed widespread, from North Africa (Morocco) to Indonesia.

References Grimaud-Herv´e D et al. 2002. Le deuxi`eme homme en Afrique. Guides de la pr´ehistoire mondiale. Collection de Pal´eontologie Humaine. Paris: Eds Artcom et Errance. Holloway RL. 1981. Volumetric and asymmetry determinations on recent hominid endocasts: Spy I and II, Djebel

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Ihroud I, and the Sale Homo erectus specimens, with some notes on Neanderthal brain size. Am J Phys Anthropo 55:385–393. Jaeger JV. 1975. Decouverte d’un crane d’hominide dans le Pleistocene moyen du Maroc. Colloque International CNRS No. 218 (Paris, 4–9 Juin 1973). Paris: CNRS. Problemes actuels de paleontologie-evolution des vertebres, pp 897–902. Saban R. 1982. Les empreintes endocrˆaniennes des veines m´ening´ees moyennes et les e´ tapes de l’´evolution humaine. Ann Pal´eontol Hum (Vert-Invert) 68:171–220.

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Figure 73. Endocranial views (scale = 1 cm).

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Figure 74. Stipple drawing demonstrating the meningeal pattern (scale = 1 cm).

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Ng andong (Solo)

Ngandong 13 (Solo X)

Gross Description

Ngandong 13 is roughly as complete as Solo V, but the temporal lobes on the right side are more complete. There is some depressed distortion on both left and right sides in the Slyvian fissure region, and the right occipital region.

Ngandong 1, 6, 7, 13, and 14 brain endocasts were described in Holloway (1980), and this publication should be consulted for illustrations.

Ngandong 1 (Solo I) The Ngandong 1 endocast is missing the basal portion, and the endocast is distorted in the region of the right Sylvian region and the posterior temporal and inferior parietal lobes of the left side.

Ngandong 14 (Solo XI) Ngandong 14 has most of the base complete except for a small portion of the rostral bec. It is more distorted than Solo VI, having a deeper right temporal pole and skewed left frontal region on the dorsal surface.

Ngandong 6 (Solo V) Ngandong 6 is the largest of the Solo group. It is missing the basal portion from a level inferior to the frontal poles to midcerebellar lobes but does retain some of the middle portions of the temporal lobes. There is distortion on the right side, giving a collapsed appearance to the temporal lobe.

Volume and Method Ngandong 1 yielded a volume of 1172 ml (see Holloway, 1980 for previous volumes). Ngandong 6 has a volume of 1251 ml. Ngandong 7 yielded a volume of 1013 ml. Ngandong 13 yielded a volume of 1231 ml. Ngandong 14 provided a volume of 1090 ml. All of these endocasts were measured by means of water displacement, and have reliabilities of A1.

Ngandong 7 (Solo VI) Ngandong 7 is the most complete of the group, missing a small portion of the rostral bec. Teuku Jacob (pers. comm.) says that the bec portion has been cleaned out and is quite deep. There is some slight distortion in the left temporal region.

Endocast Details Ngandong 1 No sulcal or gyral markings are interpretable. There is a left-occipital petalia combined with a right frontal width petalia. The right transverse receives the flow from the sagittal sinus.

The Human Fossil Record, Volume 3, by Ralph L. Holloway, Douglas C. Broadfield, and Michael S. Yuan. C 2004 John Wiley & Sons, Inc. ISBN 0-471-41823-4 Copyright


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Ngandong 6

Ngandong 6

No sulcal or gyral details. There is a left-occipital (width), right-frontal petalial pattern. The right transverse receives the flow from the sagittal sinus. The left Broca’s cap region is larger than the right, but it has been somewhat damaged postmortem.

The maximum left and right chord lengths through frontal and occipital poles are 177 mm. The maximum breadth is 133 mm; the maximum height is 109 mm.

Ngandong 7 No sulcal or gyral morphology is safely interpretable. There is a left occipital–right frontal width petalial combination. The transverse sinuses appear nearly equal in receiving flow from the confluens, but we believe the right side was favored as it is slightly thicker.

Ngandong 13 No sulcal or gyral morphology is apparent. The temporal lobes show the same tucked-under appearance of their poles as in Solo VI and XI. The petalial pattern is difficult to score given the breakage of the cranium in the right occipital region. The left frontal appears wider, but the occipital is unclear. The right transverse sinus received the major flow from the sagittal sinus.

Ngandong 14 There is very little in the way of sulcal markings, except in the left Broca’s cap region, which is clearly larger than the right side. There is a left occipital–right frontal petalial pattern, and the meningeal markings are clearest on this endocast, showing both anterior and posterior branches of the middle meningeal vessels. We believe the right transverse sinus received most of the flow from the sagittal sinus.

Morphometric Data Ngandong 1 The maximum left chord length between frontal and occipital poles is 164 mm; the right side is 163 mm. The maximum chord breadth is ca. 135 mm. The maximum height from deepest temporal lobes to vertex is 104 mm.

Ngandong 7 The maximum left chord length is 161 mm; the right side is 162 mm. The maximum chord breadth is 126 mm, and the maximum height is 98 mm.

Ngandong 13 The left and right maximum chord lengths between frontal and occipital poles are 174 mm. The maximum breadth is 134 mm; the maximum height is 106 mm.

Ngandong 14 The left and right maximum chord lengths are 166 mm. The maximum breadth is 123 mm; the maximum height is 104 mm.

Significance These brain endocasts show cohesion of size and morphometric values, as shown by Holloway’s (1980) statistics on standard deviations and coefficients of variation. Four of the five show petalial patterns consistent with right-handedness, and where available, Broca’s caps favor the left side. Given the younger age (100–40 Ka), it would be amazing if these hominids, with brain sizes well within modern human ranges, were not to have cognitive capacities similar to modern humans. We also believe that these fossil hominids retain morphology similar to the Sangiran specimens, and do not display a morphology similar to specimens such as La Chapelle.

References Grimaud-Herv´e D. 1994. Evolution of the Javanese fossil hominid brain. Cour Forsch Inst Senckenberg 171:61–68. Holloway RL. 1980. Indonesian “Solo” (Ngandong) endocranial reconstructions: Some preliminary observations and comparisons with Neanderthal and Homo erectus groups. Am J Phys Anthropo 53:285–295.

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Figure 75. Ngandong 1 (scale = 1 cm).

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Figure 76. Ngandong 1. Stipple drawing demonstrating the meningeal pattern (scale = 1 cm).

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NGANDONG (SOLO)

Figure 77. Ngandong 6 (scale = 1 cm).

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Figure 78. Ngandong 6. Stipple drawing demonstrating the meningeal pattern (scale = 1 cm).

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NGANDONG (SOLO)

Figure 79. Ngandong 7 (scale = 1 cm).

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Figure 80. Ngandong 7. Stipple drawing demonstrating the meningeal pattern (scale = 1 cm).

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NGANDONG (SOLO)

Figure 81. Ngandong 13 (scale = 1 cm).

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Figure 82. Ngandong 14 (scale = 1 cm).

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appear more rounded than in other Indonesian casts. Broca’s caps are well represented on both sides, with the left definitely more protrusive in the inferior directions, while the right Broca‘s cap is more laterally projecting. Nevertheless, the left whole cap appears larger than the right. In addition the right cerebellar lobe appears somewhat larger than the left with regard to width (49.4 mm vs. 46.2 mm: Broadfield et al. 2001: 374). There are no convolutional details that stand out unambiguously, and the occipital lobes were probably large in this hominid, judging by the grooving anterior to the lambdoid suture, to which there appears to be a good case to be made for the termination of the interparietal sulcus. The meningeal vessels are very strongly marked, with the middle meningeal on the left side issuing from the foramen spinosum, and bifurcating into three branches—the posterior, the middle branch, and a recurved anterior branch going toward the Sylvian fissural apex—and coursing forward onto the frontal lobe, as well as following the coronal suture.

SAMBUNGMACAN 3 (SM 3)

Gross Description The endocast of this specimen is perhaps the most complete discovered to date, requiring reconstruction of only the frontal orbital surface, the temporal poles, brain stem, and anterior portions of the cerebellar lobes. It is also undistorted. The full description of the endocast is in Broadfield et al. (2001).

Volume and Method Two endocast reconstructions were made: (1) Broadfield’s was 921 ml, and (2) Holloway’s was 914 ml, giving an average of 917 ml. Water displacement was used to measure the volume. The reliability is A1.

Endocast Details The endocast appears more globular in shape than all previous Indonesian endocasts. There is a left occipital petalia depending on the orientation of the endocast, at least with respect to width, but not in length, as the right occipital pole is slightly more posterior. There is a right frontal petalia in width. The frontal lobes

Morphometric Data The left maximum chord length from frontal to occipital poles is 154 mm, and the right side is 153 mm, the difference due to less projecting frontal pole. The left lateral arc is 197 mm, and the right is 200 mm. The left dorsal arc is 216 mm, and the right side is 220 mm. The maximum chord breadth is 121 mm, while the arc breadth is 192 mm. The maximum height from lowest temporal lobe to vertex is 99 mm. The bregma-deepest

The Human Fossil Record, Volume 3, by Ralph L. Holloway, Douglas C. Broadfield, and Michael S. Yuan. C 2004 John Wiley & Sons, Inc. ISBN 0-471-41823-4 Copyright


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cerebellum is ca. 115 mm. The bregma-basion chord is ca. 103 mm. The bregma-lambda chord is 83 mm, and the arc is 88 mm. The biasterionic chord breadth is 94 mm, and the lateral arc (across the transverse sinuses) is ca. 105 mm. The dorsal biasterionic arc is ca. 140 mm. The left bregma-asterion chord is 105 mm; the right side is 106 mm. Their respective arcs are left 120 mm, right 125 mm.

Significance This specimen was “discovered” in the (New York City) Upper West Side curio shop (“Maxilla and Mandible”), and its owner brought it to the attention of the American Museum of Natural History from whence it was returned to Indonesia after being described (Marquez et al., 2001; Delson et al., 2001). The endocast is significant in that its shape is more globular, with the Broca’s caps asymmetrically enlarged. This roundness, plus the lower size of the endocranial volume,

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allows the speculation that this specimen was most probably a female, and indeed, her earliest name was “Madeliene” Unfortunately, there is not yet a firm date for the find.

References Broadfield DC, Holloway RL, Mowbray K, Silvers A., Yuan MS, M´arquez S. 2001. Endocast of Sambungmacan 3 (Sm 3): A new Homo erectus from Indonesia. Anat Rec 262:369–379. Delson E, Harvati K, Reddy D, Marcus LF, Mowbray K, Sawyer GJ, Jacob, M´arquez S. 2001. The Sambungmacan 3 Homo erectus calvaria: A comparative morphometric and morphological analysis. Anat Rec 262: 380–397. M´arquez S, Mowbray K, Sawyer GJ, Jacob T, Silvers A. 2001. A new fossil hominid calvaria from IndonesiaSambungmacan 3. Anat Rec 262:344–368.

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Figure 83. Sm 3 (scale = 1 cm).

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Sangiran

Gross Description

for the superior part on the left side, the brain stem and foramen magnum region and the anterior cerebellar lobes. The posterior margin of the foramen magnum is present. The missing portions were reconstructed with plasticene.

Sangiran 2 This is a dorsal calotte portion of the brain endocast. The base is missing, including the temporal poles, but the superior and medial portions of the temporal lobes are present, as well as the posterior and lateral parts of the cerebellar lobes. The dorsal portion is undistorted.

Sangiran 17 Sangiran 17 is a mostly completely endocast, missing only the medial poles of the temporal lobes, and the orbital portion of the frontal lobe, except for the Broca’s cap regions. Some small fragments on the dorsal parietal surface are missing. The shape is typical of all the Indonesian endocasts, namely platycephalic.

Sangiran 3 This is an endocranial fragment of mostly the right parietal, some left, and a portion of the occipital lobe. Entirely missing is the base, temporal, frontal, and cerebellar lobes.

Volume and Method

Sangiran 4 This somewhat distorted endocast is missing only the frontal lobes. The cranial portions were extremely cracked, and no cerebral details are present.

Sangiran 2 The original endocast was made using latex rubber stabilized with plaster. Plasticene was added to the missing portions following the curvatures of the dorsal endocast. Holloway (1981) relied also upon the reconstructions of McGregor on Trinil 2 (Pithecanthropus I) and the complete base of Sangiran 17. A volume of 813 ml was determined by water displacement. The reliability is A1. Boule and Vallois (1957) reported a volume of 815 ml, and Tobias (1971) provided a volume of 775 ml. (See Holloway, 1981, for details regarding the earlier volume determinations and methods used.)

Sangiran 10 This is a dorsal portion of brain endocast, missing the entire base, temporal poles, orbital and prefrontal parts of the frontal lobes, but retaining the posterior portion of the frontal lobe on the left side.

Sangiran 12 This is a posterior half of the brain endocast, missing the entire frontal lobe, most of the temporal lobes, except

Sangiran 3

The Human Fossil Record, Volume 3, by Ralph L. Holloway, Douglas C. Broadfield, and Michael S. Yuan. C 2004 John Wiley & Sons, Inc. ISBN 0-471-41823-4 Copyright


There is not enough material to provide more than a few measurements, and a complete reconstruction would

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be entirely speculative. The right parietal appears as large as Sangiran 12, 17, and Trinil I. Based on this comparison, we estimate the endocranial volume to be between 950 and 1000 ml.

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The meningeal patterns have been beautifully detailed by Saban (1984) and more recently by his student, Dominique Grimaud-Herv´e, in her treatise (1997).

Sangiran 3 Sangiran 4 After reconstructing a frontal lobe based on those present in Trinil 1, Sangiran 2, and Sangiran 17, the volume determined by water displacement method was 908 ml. Von Koenigswald (1962) and Jacob (1966) both report an estimate of 750 ml.

Sangiran 10 Holloway (1981) found a volume of 855 ml, using the water displacement method on his reconstruction of the total endocast. The reliability is A1. von Koenigswald (1962) reported a volume of 975 ml.

Sangiran 12 Holloway (1981) reported a volume of 1059 ml, the largest thus far for an Indonesian hominid of this morph. Tobias (1971) listed a volume of 915 ml. We regard the reliability of Holloway’s (1981) reconstruction as A1.

Sangiran 17 The reconstructed volume was determined to be 1004 ml (Holloway, 1981). That reconstruction was based on the alignment of cranial fragments as shown in that same reference. The reliability is A1.

Endocast Details Sangiran 2 Previous workers (Kappers and Bouman, 1939; Weidenreich, 1943; Connolly, 1950) have depicted the convolutional details on this endocast. They determined, in particular, that the frontal lobe bears more of a resemblance to modern humans than Pan, and defined the lunate sulcus and lateral calcarine sulci of the occipital lobe. The interparietal remains are, however, too broad to allow identification of its course or branches. We note that the left Broca’s cap region is clearly more laterally protuberant than the very tiny part available on the right side. Indeed, the endocast does show a definite left occipital petalia (both posterior and lateral) and a large right frontal petalia, a combination often associated with right-handedness.

No details are available except for some of the meningeal vessels, of which the middle branch of the middle meningeal appears the largest.

Sangiran 4 No convolutional details are present on this endocast. There is a definite, but slight, left occipital petalia, both posterior and lateral.

Sangiran 10 There is a small left occipital petalia in length but not in width. The missing frontal lobes rule out any frontal petalia being observed. The left Broca’s cap region appears quite laterally protuberant. There are some convolutional details present on the left and right occipital lobes, and left parietal region, which suggest an upper arm for the postcentral gyrus as well as parts of the angular gyrus more posteriorly and inferiorly. These minor tertiary sulci are not very clear. If there is indeed a lunate sulcus, its anterior limit appears to be posterior to the lambdoid suture. The occipital lobe does appear larger on the right than left side. The sinus drainage pattern is difficult to see, but from the broader transverse sinus on the right side, one can expect the sagittal sinus to have drained toward the right side mostly.

Sangiran 12 The sulcal details are poor on this endocast, but the meningeal patterns are very clear. The occipital petalia appears to be only slightly larger on the left side, but the occipital poles are very asymmetric and posteriorly deflected. The width appears greater on the left side. The sagittal sinus flow is clearly to the right side. The posterior branch of the middle meningeal vessel is large and extensively bifurcated.

Sangiran 17 This endocast, nearly complete, is also relatively undistorted. There appears to be a slight left occipital petalia in width, and also in length when viewed dorsally. The right occipital pole is bounded inferiorly by a thick lateral sinus, which extends the occipital pole more posteriorly when the endocast is rotated superiorly. There is a slight, but clear right frontal petalia in width. The right occipital pole shows a possible lunate sulcus on

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its lateral and dorsal aspect that is not produced by the lambdoid suture. While there is some damage to the right Sylvian fissural region, the right Broca’s cap region is clearly smaller and less projecting, both laterally and inferiorly, than the left side. The left middle frontal convolutions show some relief; otherwise, there is little discernable convolutional detail on the remaining parts of the endocast. The cranial base is nicely preserved from basion anterior to the caudal portion of the sella turcica, which is not present. The meningeal vessels are clearly visible on the inferior surface of the temporal lobe, bifurcating immediately after issuing from the foramen spinosum into strong anterior and posterior branches. On the left side, there appears to be a middle ramus of the middle meningeal vessel as well. Both transverse sinuses are large, the main flow from the sagittal sinus going to the right side.

Morphometric Data Sangiran 2 The maximum chord length from frontal to occipital poles is 148 mm, and the lateral arc is ca. 190 mm, while the dorsal arc is 202 mm. The maximum chord breadth is 120 mm, and the arc breadth is 192 mm. The maximum depth vertex to lowest temporal lobe is 93 mm, and the bregma to basion ca. 95 to 100 mm. The bregma-lambda chord is 70 mm, and the arc is 72 mm. The biasterionic chord width is 92 mm. Maximum cerebellar width is 114 mm between the sigmoid sinuses.

Sangiran 3 We estimate the bregma-lambdoid suture chord to be ca. 87 mm (the lambdoidal suture zone is poorly represented), and the arc length to be 91 mm. We estimate the biasterionic chord breadth as between 95 and 100 mm.

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Sangiran 10 The maximum chord length between frontal and occipital poles is estimated to be ca. 156 mm. The lateral arc length, left side, is ca. 195 mm, and the dorsal arc is ca. 205 mm. The maximum chord breadth is 118 mm; the arc breadth is 183 mm. The maximum height from the vertex to the deepest temporal lobe is ca. 94 mm, and the bregma-basion chord length is 102 mm. The bregma-lambda chord length is ca. 82 mm, and the arc length is ca. 89 mm. The bregma-deepest cerebellum is ca. 117 mm. The biasterionic chord breadth is 85 mm, and the lateral biasterionic arc length is ca. 95 mm. The bregma-asterion (left) chord is ca. 113 mm, and the arc is ca. 133 mm. The dorsal arc for the biasterionic breadth is ca. 135 mm. The maximum cerebellar width is ca. 96 mm, and across the sigmoid sinuses the width is 101 mm.

Sangiran 12 The maximum chord length between occipital poles and reconstructed frontal poles is ca. 160 to 165 mm. The lateral arc length taken on the left side is ca. 205 mm, and the dorsal arc length is 235 mm. These are somewhat different by a few millimeters from Holloway’s (1981) values, due to the measurements being done on different casts. The maximum chord breadth is 130 mm, and the dorsal arc breadth is ca. 205 mm. The bregmabasion length is ca. 111 mm, and the maximum height over the vertex to the deepest temporal lobe is ca. 100 mm. The bregma-lambda chord is ca. 92 mm, and the arc length is 97 mm. The widest cerebellar breadth is ca. 100 mm, and between the sigmoid sinuses the width is ca. 103 mm. The biasterionic chord breadth is ca. 96 mm. The lateral arc is ca. 102 mm, and the dorsal arc is ca. 135 mm. The bregma-asterion chord is ca. 104 mm, and the arc is ca. 130 mm. The bregmadeepest cerebellum is ca. 125 mm. The widest cerebellar breadth is ca. 102 mm, and the widest part between sigmoid sinuses is ca. 105 mm.

Sangiran 4 The following measurements are estimated: the maximum chord length is 156 mm, and the arc length is 205 mm. The maximum chord breadth is 125 mm, and the arc breadth is 195 mm. The height, from the vertex to the lowest temporal lobe, is 95 mm. The bregmabasion length is 98 mm. The biasterionic chord breadth is ca. 73 mm. The bregma-asterion chord and arc lengths are estimated at ca. 112 and 135 mm, respectively.

Sangiran 17 The left chord length between frontal and occipital poles is 161 mm; the right side is also 161 mm. The left lateral arc length is 207 mm; the right side is 209 mm. The left dorsal arc length is 207 mm; the right side is 216 mm. These differences are due to the transverse sinus causing inferior displacement of the occipital pole on the right side.

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The maximum chord breadth is 131 mm; the arc breadth over vertex is 213 mm. The bregma-basion length is ca. 110 mm; the maximum height from deepest temporal lobes to vertex is 97 mm. The bregma-lambda chord is ca. 93 mm; the arc length is ca. 96 mm. The left bregma-asterion chord length is ca. 115 mm; the right side is 114 mm. The left arc length is 140 mm; the right side is 142 mm. The biasterionic chord width is 101 mm, and the lateral arc is 120 mm, while the dorsal arc is ca. 167 mm. The maximum cerebellar width is 104 mm; the maximum sigmoid sinus width is 107 mm.

Significance Sangiran 2 This was the second Indonesian fossil find made after Dubois’s 1891 original discovery, and it provides morphological evidence for a taxon showing surprisingly little variability. The presence of petalias and asymmetrical Broca’s cap regions is important in indicating a neurological organization, at least of the cerebral surface, concordant with that found in modern humans. While this is not a proof of symbolic language or an index of their cultural complexity, it is difficult to understand how, with the requisite structures present, this hominid did not have a cognitive capacity similar to our own.

Sangiran 3 This specimen is not of any particular significance.

Sangiran 4 The volume is clearly more than the perceived minimum of 750 ml for this taxon, but given the disparity between our volume and that of von Koenigswald and Jacob cited above, this specimen should be re-done. The presence of a left occipital petalia suggests that this specimen probably was quite similar to the remaining Indonesian specimens, and similar to modern humans in that respect.

Sangiran 10 This endocast adds to our understanding of the variability within the Indonesian hominids currently classified as H. erectus, and again, it underlines that these hominids had a characteristic morphology with

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seemingly little actual variability as far as endocranial features are concerned.

Sangiran 12 This is the largest of the Indonesian hominid brain endocasts currently classified as H. erectus with a value well within the lower range of modern humans. It is hoped that the variations in the volumes and linear measurements will prove to be useful some day in calculating volumes for less complete specimens.

Sangiran 17 This specimen is particularly important because most of the base is intact, and there is almost a complete face to the cranium. The volume is large, within the lower range of modern humans, and the brain endocast shows strong asymmetry, particularly in the left Broca’s cap region, as well as a right-hander’s petalial configuration. These too are modern human attributes, and we feel comfortable in speculating that this hominid possessed a rudimentary language and was right-handed.

References Boule M, Vallois HV 1957. Fossil Men. New York: Dryden Press. Connolly CJ. 1950. External Morphology of the Primate Brain. Springfield, IL: CC Thomas. ´ Grimaud-Herv´e D. 1997. L’Evolution de L’encep´ephale chez Homo erectus et Homo sapiens. Cahiers de Pal´eoanthro´ pologie. Paris: CNRS Editions. Holloway RL. 1981. The Indonesian Homo erectus brain endocasts revisited. Am J Phys Anthropo 55:503–521. Jacob T. 1966. The sixth skull cap of Pithecanthropus erectus. Am J Phys Anthropol 25:243–260. Kappers CUA, Bouman KH. 1939. Comparison of the endocranial casts of the Pithecanthropus erectus skull found by Dubois and von Koenigswald’s Pithecanthropus skull. Kon Nederl Akad van Wetens 42:30–40. Saban R. 1984. Anatomie et e´ volution des veines m´ening´ees ´ chez les homes fossiles. Paris: ENSB-CTHS, Editions. Tobias PV. 1971. The Brain in Hominid Evolution. New York: Columbia University Press. Weidenreich F. 1943. The skulls of Sinanthropus pekinensis: A comparative study on a primitive hominid skull. Paleontol Sin, ns D 10:1–485. von Koenigswald GHR. 1962. The Evolution of Man. Ann Arbor: University of Michigan Press.

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Figure 84. Sangiran 2. (scale = 1 cm).

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Figure 85. Sangiran 2. Stipple drawing demonstrating the meningeal pattern (scale = 1 cm).

Figure 86. Sangiran 3. Dorsal view (left); occipital view (right) (scale = 1 cm).

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Figure 87. Sangiran 10 (scale = 1 cm).

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Figure 88. Sangiran 10. Stipple drawings accenting features of the endocast (top) and the meningeal pattern (bottom) (scale = 1 cm; top image not to scale).

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Figure 89. Sangiran 12 (scale = 1 cm).

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Figure 90. Sangiran 12. Stipple drawings accenting features of the endocast (top) and the meningeal pattern (bottom) (scale = 1 cm; top image not to scale).

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Figure 91. Sangiran 17 (scale = 1 cm).

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Figure 92. Sangiran 17. Stipple drawings accenting features of the endocast (top) and the meningeal pattern (bottom) (scale = 1 cm; top image not to scale).

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Trinil

TRINIL 2

measurements clearly larger in Trinil 2 in all dimensions, we regard the figure of 940 ml as accurate, pending an independent assessment by other workers.

Gross Description

Endocast Details

Trinil 2 is a complete and undistorted dorsal calotte portion of the endocast, with only the base missing. It includes the anterior cerebellar lobes, frontal orbital surface, and temporal lobes.

The frontal lobe shows a fair degree of convolutional detail, some of it described earlier by Dubois (1924, 1929, 1933), and later by Kappers (1929) and Kappers and Bouman (1939), with comments also by Connolly (1950). Superior, middle, and inferior frontal convolutions are separated by the respective sulci, and the impression we have is that the degree of folding is well within that found in modern humans. The Broca’s cap areas are asymmetrical, with the left showing more lateral protrusion than the right, despite the missing and thus reconstructed portions on that side. The right side is not damaged. There is a definite, but small, left occipital petalia in both length and breadth, and the occipital poles are very asymmetrical, the left displaced inferiorly to the right by almost 8 to 10 mm. The right frontal petalia is very slight. The occipital lobe shows a lunate sulcus on the left side, just slightly posterior to the lambdoid suture. The right side is unclear. The sagittal sinus flows into a large right transverse sinus, which may have been a causal factor in the asymmetry of the occipital poles.

Volume and Method Holloway (1981) reported a volume of 940 ml, based on the discovery of some of McGregor’s earlier reconstructions of the basal portion of the brain endocast, and using the water displacement method. The reliability is A1. Holloway’s (1981) figure differs significantly from the early value of 750 ml, given by Weidenreich (1943) and Jacob (1966), and Tobias’s (1971) 850 ml. Tobias (1991) believes that this is more accurate than Holloway’s, citing Weidenreich’s opinion that McGregor added too much plasticene to the base (particularly the cerebellar lobes) in his reconstruction. The cerebellar lobes of McGregor’s reconstruction appear normal to us, rather than falsely enlarged. With Sangiran 2 having a volume of 813 ml and the morphometric

Morphometric Data

The Human Fossil Record, Volume 3, by Ralph L. Holloway, Douglas C. Broadfield, and Michael S. Yuan. C 2004 John Wiley & Sons, Inc. ISBN 0-471-41823-4 Copyright


The maximum chord lengths between frontal and occipital poles are 158 mm left side and 158 mm right

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side; the lateral arc length, left side, is ca. 200 mm and, right side, is ca. 200 mm. The dorsal arc length is 220 mm left side and 205 mm right side. The maximum chord breadth is 125 mm, and the arc is 205 mm. The bregma-basion length is ca. 110 mm. The height, from the vertex to the lowest temporal lobe, is estimated to be 98 mm. The bregma-lambda chord is 83 mm while the arc is 87 mm. The bregma-deepest cerebellum is ca. 112 mm. The biasterionic chord breadth is ca. 92 mm. The lateral biasterionic arc is ca. 107 mm, and the dorsal biasterionic arc length is ca. 150 mm. The bregma-asterion chord and arc length are estimated as ca. 110 mm and 132 mm, respectively. The widest cerebellar width on McGregor’s reconstruction is ca. 100 mm, and between the sigmoid sinuses 104 mm. The meningeal vessels are beautifully represented on the endocast surface, and have been elegantly described by Saban (1984) and Grimaud-Herv´e (1997). The middle meningeal bifurcates on the superior temporal lobe, close to the Sylvian fissural apex, sending posterior and middle branches superiorly and posteriorly that are quite strong.

Significance The historical significance is nothing short of fantastic, given that Dubois set out to discover one of our earliest ancestors and did so! The brain endocast volume falls within the lowest end of the range for modern humans. The more modern appearance of Broca’s region, in addition to its left lateral protuberance, signals the possibility of a cognitive pattern very similar to our own.

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References Connolly CJ. 1950. External Morphology of the Primate Brain. Springfield, IL: CC Thomas. Dubois E. 1924. On the principal characters of the cranium and brain, the mandible and the teeth of Pithecanthropus erectus. Proc R Acad Amsterdam 27:264–278. Dubois E. 1929. The fissures on the frontal lobes of Pithecanthropus erectus. Proc R Acad Amsterdam 32:182. Dubois E. 1933. The shape and size of the brain in Sinanthropus and in Pithecanthropus. Proc R Acad Amsterdam 36:1–9. ´ Grimaud-Herv´e D. 1997. L’Evolution de L’encep´ephale chez Homo erectus et Homo sapiens. Cahiers de Pal´eoanthropologie. Paris: CNRS Editions. Holloway RL. 1981. The Indonesian Homo erectus brain endocasts revisited. Am J Phys Anthropo 55:503–521. Jacob T. 1966. The sixth skull cap of Pithecanthropus erectus. Am J Phys Anthropol 25:243–260. Kappers CUA. 1929. The fissures of the frontal lobes of Pithecanthropus erectus Dubois compared with those of Neanderthal man, Homo recens and chimpanzee. Proc R Acad Amsterdam 36:802–812. Kappers CUA, Bouman KH. 1939. Comparison of the endocranial casts of the Pithecanthropus erectus skull found by Dubois and von Koenigswald’s Pithecanthropus skull. Kon Nederl Akad van Wetens 42:30–40. Saban R. 1984. Anatomie et e´ volution des veines m´ening´ees ´ chez les hommes fossiles. Paris: ENSB-CTHS, Editions. Tobias PV. 1971. The Brain in Hominid Evolution. New York: Columbia University Press. Tobias PV. 1991. Olduvai Gorge: The Skulls, Endocasts, and Teeth of Homo habilis. Cambridge: Cambridge University Press.

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Figure 93. Trinil 2 (scale = 1 cm).

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Figure 94. Trinil 2. Stipple drawing accenting the meningeal pattern (scale = 1 cm).

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Zhoukoudian (Choukoutien): Lower Cave

Skull III, Locus L (Skull III, L)

SKULL III LOCUS E

The brain endocast is mostly complete, except for the right temporal bone and left medial temporal lobe portion and pole. The rostral bec is also missing, and so are the anterior portions of the cerebellar lobes and brain stem. There is an extreme degree of sagittal keeling on the left side.

Gross Description Skull III, Locus E (Skull III, E) This nearly complete and undistorted brain endocast lacks most of the base to midcerebellar level but includes the left orbital region of the frontal lobe. The midtemporal poles are missing. Evidence of open sutures suggests that this individual was an adolescent. There is good detail of meningeal vessels.

Volume and Method Skull III, E We found a volume of 890 ml on RLH’s endocast copy using water displacement technique. Weidenreich (1943) lists a volume of 915 ml. We believe that the 915 ml is more correct, with a reliability of A1.

Skull I, Locus L (Skull I, L) The brain endocast consists mostly of the dorsal portion, missing most of the base from just inferior to the frontal poles to roughly the midcerebellar level, and missing both medial portions of the temporal lobes. Both left and right Broca’s cap regions are missing. The endocast is undistorted, and has very little sulcal morphology available. There is a strong sagittal keel on the endocast.

Skull I, L Weidenreich (1943) lists a volume of 1220 ml. We have not independently tested the volume on our endocast copy. We expect the reliability to be A1.

Skull III, L Weidenreich (1943) found a volume of 1030 ml using water displacement on a reconstructed endocast. Our copy has a volume of 1023 ml. The reliability is A1. We will continue to use Weidenreich’s determination.

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Endocast Details Skull III, E We refer the reader to Black (1931) for the full description. There is clearly defined left occipital and right frontal petalial pattern suggesting right-handedness. The left occipital petalia exists for both length and width. The left Broca’s cap region is larger than the right, if one considers the fissure on the left side that runs through the cap region. Superior, middle, and inferior frontal convolutions can be distinguished but not the tertiary variations within each. The longitudinal sagittal sinus is strongly elevated and flows very clearly to the right transverse sinus, which is as developed as the left transverse sinus. Superior and inferior temporal sulci are seen on both sides. The parietal lobes show very little convolutional detail, except that the right inferior parietal/superior temporal region shows a strongly projecting inferior parietal lobule. The occipital lobes are without sulcal relief, and it is possible that the dorsal extent of the lunate sulci was located just posterior to the lambdoid suture, although the posterior and inferior edge of the parietal bones does make a deeper furrow. The posterior rami of the middle meningeal vessels are strongly represented on the superior temporal and posterior parietal regions.

Skull I, L There is a very strong and clear left occipital petalial pattern, both in length and width. With the frontal lobes missing at their widest region, it is difficult to be certain, but in Weidenreich’s (1937, 1943) reconstruction, which carefully follows the anterior frontal lobe contours, and the parietal lobe, there does appear to be a suggestion of a right frontal width petalia. The right frontal pole is more anteriorly situated, reinforcing our conclusion. There are no sulcal details seen on our cast. The sagittal sinus appears to flow mostly to the right, but this region is not very clear in our copy.

Skull III, L There is a left occipital petalia in both length and width, although the right occipital lobe appears deformed. There is a small right frontal width petalia, and the left frontal pole is more anteriorly projecting. The right Broca’s cap region appears larger than the left, and more inferiorly projecting. The left Broca’s cap appears slightly more laterally projecting than the right side. The left Broca’s cap shows enough detail so that

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it is possible to distinguish the pars triangularis from the pars orbitalis and pars opercularis regions. This is not possible on the right side. The parietal, temporal, and occipital lobes appear devoid of sulcal detail, and the occipital lobes show the same kind of rounding as in Skull III. The transverse sinuses are wide but indistinct, and the sagittal sinus appears to flow to the right side. The posterior ramus of the middle meningeal vessel is strongly marked on the left side.

Morphometric Data Skull III, E The left chord length between frontal and occipital poles is 160 mm; the right side is 161 mm. The left lateral arc length is 203 mm; the right side is 200 mm. The left dorsal arc length is 210 mm; the right side is 210 mm. The maximum chord breadth is 122 mm; the arc breadth is 206 mm. The bregma-basion is ca. 108 mm; the maximum height from deepest temporal lobes to vertex is ca. 98 mm. The bregma-lambda chord length is 86 mm; the arc length is 93 mm. The left bregma-asterion chord length is 106 mm, the arc length is 130 mm, the right chord length is ca. 108 mm, and the arc is ca. 130 mm. The biasterionic breadth chord is ca. 89 mm; the lateral arc length is ca. 110 mm. The dorsal arc is ca. 160 mm. The maximum cerebellar width is 96 mm, and 106 mm between the sigmoid sinuses. All of these measurements are on the 890 ml endocast copy.

Skull I, L The left chord length between frontal and occipital poles is 178 mm; the right side is 175 mm. The left lateral arc length is 234 mm; the right side is 216 mm. The left dorsal arc length is 238 mm; the right side is 239 mm. The maximum chord width is ca. 133 mm; the arc width over vertex is 220 mm. The bregma-basion chord length is ca. 120 mm; the maximum height is ca. 118 mm on our reconstructed cast. The bregma-lambda chord is ca. 103 mm; the arc length is ca. 112 mm. The bregma-deepest cerebellum is ca. 126 mm. The left bregma-asterion chord is ca. 117 mm; the arc length is ca. 143 mm. The right chord length is ca. 125 mm, and the arc length is ca. 152 mm. The biasterionic chord width is ca. 95 mm; the lateral arc over the transverse sinus is ca. 120 mm, while the dorsal arc is ca. 170 mm. The maximum cerebellar width is ca. 94 mm and 110 mm between the sigmoid sinuses.

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Skull III, L

Skull I, L

The measurements that follow are from our endocast copy. The left chord length between frontal and occipital poles is 170 mm; the right side is 168 mm. The left lateral arc length is 218 mm; the right side is ca. 215 mm. The left dorsal arc length is 224 mm, and includes the humped keel on that side; the right side is ca. 220 mm. The maximum chord breadth is 128 mm; the arc breadth over vertex is 210 mm. The bregmabasion chord is ca. 112 mm; the maximum height from the lowest temporal lobes to the vertex is ca. 109 mm. The bregma-deepest cerebellum is ca. 118 mm. The bregma-lambda chord is ca. 88 mm; the arc length is 93 mm. The bregma-asterion chord length, left side, is 114 mm; the arc length is 135 mm. On the right side, these measure 113 mm and 136 mm, respectively. The biasterionic chord length is ca. 93 mm, and the arc length is ca. 112 mm. The maximum cerebellar width is 100 mm and 105 mm between reconstructed sigmoid sinuses.

The large size, well within the range of modern humans, and the extremely strong left occipital petalia suggest a high degree of cerebral lateralization and perhaps specialization. It is too bad that Broca’s caps are missing bilaterally, as they would help increase the likelihood that this hominid was very similar to modern humans in terms of cerebral asymmetries.

Significance Skull III, E The combination of adolescence and a complete dorsal endocast portion, as well as good detail on the available basal portions, makes this endocast an important template for other less complete specimens. It also enables an estimation of the lower part of the range of brain volumes in hominids of this morph.

Skull III, L The fissuration of the frontal lobe is extensive, and the left Broca’s cap region surely suggests a pattern very similar to that of modern humans. The humped keel is a curiosity requiring explanation, for which we have none.

References Black D. 1931. On an adolescent skull of Sinanthropus pekinensis in comparison with an adult skull of the same species and with other hominid skulls, recent and fossil. Palaeontol Sin, ns D 7:1–144. Weidenreich F. 1937. Reconstruction of the entire skull of an adult female individual of Sinanthropus pekinensis. Nature 139:269–272. Weidenreich F. 1943. The skulls of Sinanthropus pekinensis: a comparative study on a primitive hominid skull. Paleontol Sin, ns D 10:1–485.

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Figure 95. Skull III, Locus E (scale = 1 cm).

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Figure 96. Skull III, Locus E. Stipple drawing accenting the meningeal pattern (scale = 1 cm).

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Figure 97. Skull I, Locus L (scale = 1 cm).

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Figure 98. Skull I, Locus L. Stipple drawing accenting the meningeal pattern (scale = 1 cm).

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Figure 99. Skull III, Locus L (scale = 1 cm).

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Figure 100. Skull III, Locus L. Stipple drawing accenting the meningeal pattern (scale = 1 cm).

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Amud

Gross Description

as in modern humans. The parietal lobes appear somewhat fuller and less flat than those of Western Europe. There appears to be somewhat less occipital bunning as well. We are uncertain of whether or not a lunate sulcus can be seen. The left occipital lobe, just superior to the transverse sinus, shows a clear sulcus, which can be interpreted as the most inferior and lateral limit of the lunate sulcus. Superior to that is a horizontally oriented sulcus that appears to be the lateral calcarine sulcus. The parietals do not show the interparietal sulcus with any clarity, so the posterior position of this sulcus is not detectable. The left transverse sinus is strongly marked, and we believe that the sagittal sinus flowed mostly to the left side. The meningeal vessels are best seen on the left side, and they have the same pattern as other specimens within this morph.

Amud is the largest of the hominids of the Mousterian morphs yet found. It consists of all of the dorsal endocranial surface but is missing the basal portion of the frontal lobes, medial temporal lobes, brain stem, foramen magnum region, and parts of the inferior cerebellar lobes. The right sphenoid is also missing. The cast we possess shows some distortion in that the right parietal lobe seems to be shifted to the right of the midsagittal plane. The numerous cracks and poor quality of internal bony table has reduced the convolutional detail available for study.

Volume and Method The volume is listed as 1740 ml. Ogawa et al. (1970) used the water displacement method after adding plasticene to the base. Reliability is X1.

Morphometric Data

Endocast Details

Our cast is a plastic replica, and all measurements should be regarded as approximations. The left maximum chord length between frontal and occipital poles is ca. 190 mm; the right side is roughly the same. The left lateral arc length is ca. 230 mm, and the left dorsal arc is ca. 265 to 270 mm. Maximum chord breadth is ca. 143 mm; the dorsal arc over the vertex is ca. 274 mm. The bregma-basion length is estimated to be between 130 mm and 140 mm, while the maximum height, from the deepest temporal lobe to the vertex, is ca. 120 to 125 mm. The biasterionic breadth is ca. 120 to 125 mm; the lateral arc over the transverse sinus is ca. 140 to

The Amud endocast shows a clear left occipital petalia in both length and width, and there is a right frontal width petalia as well. While the right frontal Broca’s cap region is either missing or extensively damaged, the left Broca’s cap region is large and laterally projecting. The frontal poles are missing, but the contours immediately superior to them show a full and rounded frontal lobe The Human Fossil Record, Volume 3, by Ralph L. Holloway, Douglas C. Broadfield, and Michael S. Yuan. C 2004 John Wiley & Sons, Inc. ISBN 0-471-41823-4 Copyright


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150 mm. The left bregma-asterion chord is 140 mm; the arc length is 170 to 175 mm. The bregma-lambda chord is ca. 117 mm; the arc length is 126 mm. The maximum cerebellar width is ca. 120 mm and 128 mm between sigmoid sinus remnants.

that of modern humans. Ogawa et al. (1970) regarded the frontal lobe as small but the parietals as enlarged. We regard the frontal lobe as within the range of modern humans.

Significance

Reference

As one of the largest fossil hominid brain endocasts to date, this specimen provides also evidence of righthandedness, full frontal lobes, an enlarged left Broca’s cap, and more rounded parietal lobes. These all suggest, but do not prove, a cognitive capacity possibly equal to

Ogawa T, Kamiya T, Sakai S, Hosokawa, H. 1970. Some observations on the endocranial cast of the Amud man. In: Suzuki H, Takai F, eds, The Amud Man and His Cave Site. Tokyo: Keigaku, pp 407–420.

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AMUD

Figure 101. Endocranial views (scale = 1 cm).

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Teshik-Tash

This endocast from Moscow (found in Kazakhstan) of an approximately nine-year old boy has a clear left occipital petalia, both in length and width. The right frontal appears very slightly wider in terms of a petalia, but the left Broca’s cap appears larger than the right. Grimaud-Herv´e (1997) lists the cranial capacity as 1515 ml, but as the two readings were 1530 ml and 1520 ml, the mean would be

1525 ml. We do not have any photographs of this endocast.

Reference Grimaud-Herv´e D. 1997. L’evolution de l’encephale chez Homo erectus et Homo sapiens: Examples de L’Asie et de L’Europe. Paris: CNRS Editions.

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Figure 102. Stipple drawings accenting the meningeal pattern (scale = 1 cm).

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Arago (Tautavel)

Gross Description

most other hominid endocasts, the OH 9 specimen being the most similar in that regard. The right parietal lobe is heavily bossed in its more anterior, rather than posterior part, but it is not possible to be certain of the sulcal morphology in this region. The meningeal vessels are well marked on the right parietal, and have been described by Saban (1977, 1984) and Grimaud-Herv´e (1997, 1998).

This brain endocast is a composite reconstruction using the Arago 47 right parietal lobe, the Arago 21 frontal lobe, and the Swanscombe occipital, which fits extremely well with the Arago parietal. It is possible that the two Arago parts are from the same individual, albeit differently numbered. The Arago 21 frontal also includes the right temporal pole. The prefrontal lobe is more pointed than the Indonesian endocasts, and there is full rostral bec, which is slightly distorted on the left side.

Morphometric Data It should be remembered that the length measurements to follow are for the composite, including the Swanscombe occipital. The maximum chord length between frontal and occipital poles is ca. 177 mm; the lateral arc (right side) is ca. 232 mm; the dorsal arc length is ca. 240 mm. These might be useful in multiple regression techniques for volume estimation. The maximum chord breadth is ca. 131 mm; the arc breadth is ca. 230 mm. The biasterionic chord breadth is ca. 98 mm. The bregma-lambda chord is ca. 98 mm, and the arc length is ca. 102 mm. The right bregma-asterion chord is ca. 124 mm; the arc length is ca.150 mm.

Volume and Method The methods used in making this endocast are described in Holloway (1983). The volume, as determined by water displacement, is 1166 ml. The reliability is A2, given the composite structure of the endocast.

Endocast Details There is a right frontal width petalia, and both Broca’s cap regions are very large, the left perhaps being slightly more laterally protuberant than the right side. The pars orbitalis portion (Brodmann’s area 47) is quite large, and some traces of the pars triangularis and pars opercularis are discernible. The right temporal pole juts strongly forward, rather than being curved and flattened as in

Significance This large volume is within the lower range of modern humans and most comparable to the Zhoukoudian Lower Cave brain endocasts. The very large Broca’s cap regions are dramatic, and indeed Holloway (1983) referred to this individual as “a very garrulous individual.” Of course, this was pure speculation.

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References Grimaud-Herv´e D. 1997. L’´evolution de l’enc´ephale chez Homo erectus et Homo sapiens. Cahiers de Pal´eoanthropologie. Paris: CNRS Editions. Grimaud-Herv´e D. 1998. Le moulage endocrˆanien de l’hominid´e Arago 21 et 47. L’Anthropologie 102:21–34. Holloway RL. 1983. Homo erectus brain endocasts: Volumetric and morphological observations with some comments on cerebral asymmetries. L’Homo erectus et la

place de l’homme de Tautavel parmi les hominid´es fosiles: Congr`es International de Pal´eontologie Humaine. 1er Congr`es, Nice. 16–21 Octobre 1982, pp 355– 366. Saban R. 1977. L’´evolution du trac´e des veines m´ening´ees moyennes dans la lign´ee des Atlanthropiens. CR 102e Congr Soc Sav Limoges, Sect Sci fasc 1, Biol Veg Biol An: 423–437. Saban R. 1984. Anatomie et e´ volution des veines m´ening´ees chez les homes fossiles. Paris: ENSB-CTHS, Editions.

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A R A G O ( T A U TA V E L )

Figure 103. Endocranial views (scale = 1 cm).

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Figure 104. Stipple drawing accenting the meningeal pattern (scale = 1 cm).

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Brno

a reversal in length depending on the orientation of the endocast, although the left appears consistently wider. If the frontal portion is elevated relative to the observer, the left occipital is projective. If the endocast rests upon its base, the right appears slightly more projective. The right frontal petalia appears wider than the left. The longitudinal sinus splits into two branches toward both left and right transverse sinuses. There is a very clear enlarged marginal occipital sinus on the right side. Vlcek (1993) obtained an endocranial volume of 1304 for Brno III.

BRNO II This endocast has a strong right occipital petalia, both in length and width, while the left frontal appears wider than the right, suggesting left-handedness. The Broca’s caps are not present. Vlcek (1993) estimated the endocranial volume as 1500 ml.

BRNO III

Reference

This endocast is strongly deformed on the left side, as the left temporal/frontal region is crushed inward. The occipital petalias are difficult to unravel, as they undergo

Vlcek, E. 1993. Fossile Menschenfunde von WeimerEhrings dorf. Mit Beitr¨agen von W. Steiner, D. Mania, R. Feustel, H. Grimm & R. Saban. Stuttgart.

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Figure 105. Brno III (not to scale).

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Combe Capelle

Reference

This is a very dolichocranic endocast, with a perfect undistorted right side except for a minor break in Broca’s cap region. There is a strong left occipital petalia, both in the posterior and width dimensions. Our impression is that the right frontal petalia is larger than the left. Broca’s caps cannot be scored. The cranial capacity is given as 1570 ml (Grimaud-Herv´e, 1997).

Grimaud-Herv´e D. 1997. L’´evolution de l’enc´ephale chez Homo erectus et Homo sapiens: Exemples de L’Asie et de L’Europe. Pal´eoanthropologie. Paris: CNRS Editions.

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Figure 106. Endocranial views (not to scale).

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Cro-Magnon

CRO-MAGNON III The endocast has a clear left-occipital and right frontal petalial combination, both in length and widths. The right Broca’s cap appears large both in lateral and inferior projection. The left is missing. The cranial capacity is given as 1590 ml.

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Figure 107. Endocranial views (not to scale).

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Dolni Vestonice

Reference

DOLNI VESTONICE III

Jelinek, J. 1954. Nalez fosiliho clove ka Dolni Vestonice III. Anthropozoikum 3:37–92.

There is a very clear left occipital petalia, both in length and width, with a clear right frontal petalia in width and length. Jelinek (1954) estimated an endocranial volume of 1285 for DV III.

Figure 108. Stipple drawing accenting the meningeal pattern (not to scale).

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Feldhofer Grotto (Neanderthal)

Gross Description

sulcus, places it in a fairly posterior and modern humanlike position. The remaining endocast shows very little sulcal or meningeal detail. We remark, once again, that the frontal lobes are large and rounded as in modern humans (see also Holloway, 1985).

The brain endocast includes only the dorsal surface from the frontal poles to just inferior to the occipital poles. No basal portions are present. The shape is long, broad, and low, typical of all Western European Middle Paleolithic morphs found thus far.

Morphometric Data

Volume and Method

The left maximum chord length between frontal and occipital poles is 181 mm; the right side is 182 mm. The left lateral arc length is 227 mm; the right side is ca. 140 mm, over the elevated transverse sinus. The left dorsal arc length is 240 mm; the right side is ca. 250 mm. The maximum chord breadth is 145 mm; the arc breadth is ca. 220 mm. The bregma-lambda chord is 100 mm; the arc length is 104 mm. We estimate biasterionic width as 100 mm and the arc length ca. 110 mm. The dorsal biasterionic arc is ca. 140 mm. The left bregma-asterion chord length is 129 mm; the right side is 128 mm. The arc lengths are, respectively, left and right: 153 mm and ca. 153 mm.

The volume is given as 1525 ml (Boule, 1909). The reliability is X1.

Endocast Details There is a clear left occipital petalia, both in length and width. The right occipital extension posteriorly is due to the transverse sinus, and not the occipital pole. There is a slight right frontal width petalia, and the frontal pole on the right side is considerably larger than on the left side, also suggesting right-handedness. The left Broca’s cap region is noticeably larger than on the right side. The matter of a lunate sulcus is difficult to interpret, the right occipital lobe being smooth and without sulcal markings. The left occipital lobe does show a detectable groove some 10 mm posterior to the lambdoid suture, which if interpreted as a lunate

Significance The large volume (however calculated) and the larger left Broca’s cap region, as well as the petalial pattern, suggests right-handedness and left cerebral dominance, thus suggesting cognitive capacities within the range of modern humans.

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FELDHOFER GROTTO (NEANDERTHAL)

References Boule M. 1909. Sur la capacit´e crˆanienne des hommes fossiles du type de Neanderthal. C R Acad Sci (D) 147:1352.

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Holloway RL. 1985. The poor brain of Homo sapiens neanderthalensis: see what you please. In: Delson E, ed, Ancestors: The Hard Evidence. New York: AR Liss. pp 319– 324.

Figure 109. Endocranial views (scale = 1 cm).

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Figure 110. Stipple drawing accenting the meningeal pattern (scale = 1 cm).

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Gibraltar

on the frontal petalia, except to note that the middle prefrontal region is broader on the right side than the left, as is the frontal pole region, so a right frontal petalia is likely indicated but unproved. The preservation of internal table of bone is not good; thus there are few if any reliable sulcal morphologies to discuss. The same applies to the question of sinuses (although it appears that the sagittal sinus flowed to the right transverse sinus) and meningeal vessels.

GIBRALTAR I

Gross Description The endocast described herein is one of the reconstructions by J. McGregor, date unknown. The endocast contains most of the right side, including the frontal, temporal, some of the parietal, occipital, and cerebellar lobes. The left side is mostly missing, but the left occipital lobe is present, as well as the medial temporal lobe and pole. The basal region is mostly intact, including the rostral bec of the frontal lobe.

Morphometric Data

The endocast is labeled as having a volume of 1280 ml, yet Holloway (2000) has it listed as 1200 mm, which must be in error. The cast in our lab made by McGregor yields a volume of 1270 ml. The reliability, given the relatively completeness and McGregor’s skill, is X1.

The maximum chord length between poles on the left side is 168 mm; the right side is 168 mm. The left lateral arc is ca. 217 mm; the right side, which is more reliable, is ca. 220 mm. The left dorsal arc length is ca. 240 mm; the right side is ca. 230 mm. The maximum chord breadth is ca. 142 mm; the arc breadth over vertex is ca. 220 mm. We estimate the bregma- (missing) basion chord length as ca. 120 mm; the maximum height is ca. 113 mm. The maximum cerebellar width is ca. 110 mm. Neither bregma nor asterion landmarks are present.

Endocast Details

Significance

Volume and Method

This was actually the earliest find of the Middle Paleolithic morphs, currently designated Homo neanderthalensis, but was not appreciated as such. The small size of the endocast suggests a female, but this is speculation. The preservation of the basal portion is a major gain, and should be useful in reconstructions where this region is often missing.

The rostral bec is extremely broad. There is a left occipital petalia in length, the right occipital lobe appearing somewhat broader than the left. We cannot comment The Human Fossil Record, Volume 3, by Ralph L. Holloway, Douglas C. Broadfield, and Michael S. Yuan. C 2004 John Wiley & Sons, Inc. ISBN 0-471-41823-4 Copyright


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References Smith GE. 1928. The endocranial cast. In: Excavations of a Mousterian rockshelter at Devil’s Tower, Gibraltar. J R Anthropol Inst 58:86–91.

Holloway RL. 2000. Brain. In: Delson E, Tattersall I, Van Couvering J, Brooks AS, eds, Encyclopedia of Human Evolution and Prehistory, 2nd ed. New York: Garland, pp 141–149.

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G I B R A LTA R

Figure 111. Endocranial views (scale = 1 cm).

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Figure 112. Stipple drawing accenting the meningeal pattern (scale = 1 cm).

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Krapina

Gross Description

they are difficult to interpret given that adjacent regions are missing.

Krapina 3 (= Cranium C) The endocast for Krapina 3 contains most of the right frontal lobe, a tiny portion of left prefrontal, right temporal lobe except for the temporal pole, and most of the right parietal lobe. There is a small portion of the anterior right cerebellar lobe including the sigmoid sinus, and cerebellar/temporal lobe cleft. Missing is the posterior dorsal part of the frontal and parietal lobes, as well as the entire occipital region. The surviving portion is undistorted except for a minor displacement of frontal lobe just superior to the Broca’s cap area. There are good indications of tertiary convolutions, but they are difficult to interpret.

Volume and Method Krapina 3 A reconstruction was made by making a hemi-endocast of the right side and adding plasticene to the missing regions. The occipital portion was fashioned based on the occipital fragment for Krapina 6. The dorsal and midline contours followed the available portions. A temporal pole region, orbital surface, and brain stem region were added. Using water displacement technique, the resulting average volume was 1255 ml. We judge the reliability as A1-2.

Krapina 6 (= Cranium E) The endocast for Krapina 6 contains most of the right frontal lobe, but without an orbital surface; the posterior portion of the right temporal lobe, but without the middle and inferior temporal portions, except for the temporal pole; and most of the right parietal lobe, inferior portion of the occipital lobe, and a small portion of the superior part of the right cerebellum. There is a small portion of the left prefrontal lobe. The surviving portions are undistorted except for a minor displacement of frontal lobe just anterior to the Broca’s cap area. There are few indications of tertiary convolutions, but

Krapina 6 A reconstruction was made by making a hemi-endocast of the right side, ignoring the left prefrontal portion. The midsagittal plane was determined using the internal frontal crest and the medial edge of the small parietal fragment, which retains some residue of the sagittal suture, and by adding plasticene to the missing regions. The dorsal and midline contours followed the available portions. The temporal pole region, orbital surface, inferior cerebellum, and brain stem region were modeled after the regions on the Krapina 3 (cranium C) endocast. The endocranial volume of the reconstructed hemi-endocast was 1205 ml, as determined by water displacement. We judge the reliability as A1-2.

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Endocast Details Krapina 3 Since this is only a hemi-endocast portion, we cannot comment on possible cerebral asymmetries. The Broca’s cap region is as full as in any modern human, and the prefrontal lobe appears highly fissurated, as does the inferior parietal regions. The superior temporal gyrus is quite full, and the prefrontal portion shows a typical modern verticality and curvature. The meningeal vessels are clearly demarcated, the middle meningeal vessel arising from the foramen spinosum and immediately bifurcating into thick anterior and posterior branches. There are slight anastomoses between the smaller branches The anterior branch appears to branch into a vessel following the coronal sutural region and another more anteriorly directed fragment, just posterior to Broca’s cap, in the Sylvian cistern region.

dorsal arc over the vertex is ca. 133 mm, or 266 mm if for the complete endocast. The bregma to the deepest cerebellum is ca. 112 mm. The bregma-asterion chord length is ca. 124 mm, and the arc length is 148 mm. The greatest cerebellar width is ca. 110 mm, and the greatest sigmoid sinus breadth is ca. 124 mm.

Krapina 6 The chord length of the reconstructed right half is ca. 174 mm, while the dorsal arc length is ca. 247 mm, and the lateral arc is ca. 230 mm. The maximum breadth is ca. 67 mm, suggesting a total breadth of 134 mm. The dorsal arc over the vertex is ca. 110 mm, or 220 mm if for the complete endocast. The bregma to the deepest cerebellum is ca. 130 mm. The bregma-asterion chord length is ca. 124 mm, and the arc length is ca. 145 mm. The greatest cerebellar width is ca. 110 mm, and the greatest sigmoid sinus breadth is ca. 120 mm.

Krapina 6 Since this is only a hemi-endocast portion, we cannot comment on possible cerebral asymmetries, except to note that the small portion of left prefrontal section suggested a wider left frontal pole than that on the right side. The Broca’s cap region is unfortunately missing in its posterior and inferior portions, but judging from the anterior portion, we expect that it was as full as that of any modern human. The superior temporal gyrus in its posterior aspect is quite full, and the prefrontal portion shows a typical Homo verticality and curvature. The meningeal vessels are clearly demarcated, the middle meningeal vessel most probably arising from the foramen spinosum but becoming visible only posterior to the inferior portion of the coronal suture, where it divides into a large medial and smaller posterior branches. There are slight anastomoses between the smaller branches. The small anterior branch appears to branch into a vessel following the coronal sutural region and another more anteriorly directed fragment, just posterior to Broca’s cap.

Morphometric Data Krapina 3 The chord length of the reconstructed right have is ca. 168 mm, while the dorsal arc length is ca. 245 mm, and the lateral arc is ca. 210 mm. The maximum breadth is ca. 69 mm, suggesting a total breadth of 138 mm. The

Significance Krapina 3 We are not aware of any descriptions of the endocranial remains from Krapina, including the larger cranial portion for Krapina 6, which we are currently working up. In general, these endocast details suggest a hominid group having slightly more derived features, that is, a bit more modern than the French or Belgian members of this Middle Paleolithic morph that we have described elsewhere. The relatively low endocranial volume will lower somewhat the composite average of the group, currently designated H. neanderthalensis. We do not know whether these specimens are female or male. If Krapina 3 were a female, the overall average of this morph would probably still surpass that for modern humans as suggested by Holloway (1985).

Krapina 6 Earlier reported cranial capacities by Holloway (2000) appear to have been inflated, and these reported herein are clearly smaller than those of so-called classic Western European Middle Paleolithic morphs, although it is possible that Krapina 3 and 6 did belong to smaller females. Since we do not have both sides of the endocranial remains, we cannot be certain that the petalial asymmetry patterns were exactly the same as in other Middle Paleolithic morphs or as in modern humans.

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KRAPINA

References Holloway RL. 1985. The poor brain of Homo sapiens neanderthalensis: See what you please. In: Delson E, ed, Ancestors: The Hard Evidence. New York: AR. Liss, pp 319–324.

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Holloway RL. 2000. Brain. In: Delson E, Tattersall I, Van Couvering J, Brooks AS, eds, Encyclopedia of Human Evolution and Prehistory, 2nd ed. New York: Garland, pp 141–149.

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Figure 113. Krapina 3 (scale = 1 cm).

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KRAPINA

Figure 114. Krapina 6 (scale = 1 cm).

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La Chapelle-aux-Saints

Gross Description

Boule and Anthony (1911) depicted a lunate sulcus just anterior to the lambdoid suture on the right side, but we do not agree with this designation, as we believe it is really a groove caused by the posterior portion of the parietal bone, and we refer the readers to Symington’s (1916), and Clark et al.’s (1936) discussion of this question. The left side also shows a groove well posterior to the lambdoid suture, but we do not regard the details secure enough to definitively place the lunate sulcus. The sagittal sinus appears to be draining mostly to the right transverse sinus.

La Chapelle-aux-Saints is an almost complete brain endocast, missing only portions of the cranial base, namely orbital part of the frontal lobe, medial portions of the temporal lobe poles, and brain stem.

Volume and Method The volume of this endocast, as reported Boule (1908), is 1625 ml. The reliability is X1.

Endocast Details

Morphometric Data

This endocast shows the typical shape of a long, low, and broad brain seen in other Western European Middle Paleolithic morphs such as Gibraltar. The convolutional detail is poor, as are the details of the meningeal vessels. There is a slight left occipital petalia in length, and the occipital width is clearly larger on the left side. We believe that the left frontal shows a wider frontal petalia. Unfortunately, the left Broca’s cap region is damaged on the original skull. Our sense is that the right Broca’s cap region is larger than the left. A case can be made for a true pars triangularis on the right side. While the Sylvian fissure can be seen, in particular, at the apex, it is difficult to trace it posteriorly.

The maximum chord length, left side, between frontal and occipital poles is 184 mm, and the right side is 185 mm. The lateral arc length, left side, is 235 mm; the right side is 240 mm. The dorsal arc, left side is 254 mm; the right arc is ca. 252 mm. The maximum chord breadth is ca. 150 mm, and the arc breadth is ca. 227 mm. The bregma-basion is ca. 135 to 140 mm. The maximum height from the deepest temporal lobe over the vertex is ca. 115 to 120 mm. The bregmalambda chord length is ca. 99 mm, and the arc length is ca. 101 mm. The bregma-deepest cerebellum is ca. 140 mm. We estimate biasterionic breadth as ca. 105 to 110 mm. The arc length over the transverse sinuses is ca. 115 mm. The dorsal arc length is 170 mm. The left bregma-asterion chord length is ca. 140 mm, and the arc length is ca. 165 mm; the right side respectively is

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LA CHAPELLE-AUX-SAINTS

129 mm and 165 mm. The maximum cerebellar width is ca. 115 mm and between sigmoid sinuses is ca. 123 mm.

Significance The volume of 1625 ml is quite large, and in the upper range for modern humans. The rounded contours of the frontal lobe and large size of the right frontal Broca’s cap region are all within modern human range. Despite the low cranial height, and relatively long and broad shape, we believe there are no significant differences in the brain functional morphology from modern humans, and for this reason we continue to believe that hominids of the Middle Paleolithic of Europe are only separated from modern humans at the subspecific level. However, this a highly controversial area, as for example, Schwartz and Tattersall (1996).

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References Boule M. 1908. L’Homme fossile de La Chapelle-aux-Saints (Correze). L’Anthropol 19:519–525. Boule M, Anthony R. 1911. L’encephale de l’homme fossile de La Chapelle-aux-Saints. L’Anthropol 22:129– 196. Clark WE LeGros, Cooper D, Zuckerman S. 1936. The endocranial cast of the chimpanzee. J R Anthropol Inst 66:249–268. Schwartz JH, Tattersall I. 1996. Significance of some previously unrecognized apomorphies in the nasal region of Homo neanderthalensis. Proc Nat Acad Sci 93:10852– 10854. Symington F. 1916. Endocranial casts and brain form: a criticism of some recent speculations. J Anat Physiol 50:111– 130.

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Figure 115. Endocranial views (scale = 1 cm).

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LA CHAPELLE-AUX-SAINTS

Figure 116. Stipple drawing accenting the meningeal pattern (scale = 1 cm).

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La Ferrassie

appears considerably larger in both lateral and inferior protrusion, despite the missing left pars orbitalis region. The prefrontal portions of the frontal lobe are as rounded and voluminous as in modern humans. The remainder of the endocast shows almost no reliable convolutional detail, except in the inferior aspect of the temporal lobes. The occipital lobes show posterior protrusion, probably related to the occipital “bunning” usually discussed as a character trait for these hominids. There are detectable grooves, broad in nature, posterior to the lambdoid suture that could be lunate sulci. The transverse and sigmoid sinuses appear larger on the right side, suggesting flow to that side from the sagittal sinus. The meningeal vessels are not elaborate on this endocast, and are visible mostly on the right side. The pattern appears similar to that of La Chapelle-auxSaints.

LA FERRASSIE I

Gross Description La Ferrassie is an almost complete brain endocast missing portions of the prefrontal orbital part of the frontal lobe, the left orbital portion of the Broca’s cap, middle temporal poles, and the brain stem and foramen magnum region. It is one of the few undistorted brain endocasts available. As with other members of this morph from the Middle Paleolithic, it is a long, low, and broad brain endocast with a volume almost 300 ml larger than the modern human average (1350 ml).

Volume and Method The endocranial volume is given as 1640 ml by Heim (1970), and more recently as 1670 ml by GrimaudHerv´e (1997). The reliability is X1.

Morphometric Data The left maximum chord length between frontal and occipital poles is 186 mm; the right side is ca. 185 mm if adjusted for an excrescence on the frontal pole. The left lateral arc length is 239 mm; the right side is ca. 243 mm. The left dorsal arc is 251 mm; the right side is 251 mm. The maximum chord breadth is 152 mm; the arc breadth is ca. 258 mm. The bregma landmark and coronal suture are difficult to follow on our cast, but we estimate the bregma-basion length to be ca. 135 to 140 mm. The bregma-deepest cerebellum is ca. 140 mm. The maximum height, from deepest temporal lobe to vertex is ca. 138 mm. The biasterionic chord

Endocast Details There is a distinct left occipital petalia in length, although the right side appears slightly wider. There is clear right frontal width petalia, thus suggesting righthandedness. The right Broca’s cap region, however, The Human Fossil Record, Volume 3, by Ralph L. Holloway, Douglas C. Broadfield, and Michael S. Yuan. C 2004 John Wiley & Sons, Inc. ISBN 0-471-41823-4 Copyright


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LA FERRASSIE

breadth is ca. 120 mm, the arc width over the transverse sinuses is 135 to 140 mm. The dorsal arc is ca. 195 mm, roughly following the lambdoid suture. The bregmaasterion chords is ca. 135 mm and the arc is ca. 165 mm. The widest cerebellar width is ca. 120 mm, and the width between sigmoid sinuses ca. 125 mm.

Significance As one of the few relatively complete, large, undistorted endocranial casts associated with an almost a complete skeleton, La Ferrassie I should provide an accurate encephalization quotient if the latter can be accurately determined from body weight estimation. The very large right Broca’s cap region, which is associated with a

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right-handed petalial pattern, is unusual. We offer no speculations regarding La Ferrassie’s cognitive capacities except to note that all of the morphology we see falls well within the range of modern humans, including the roundness and verticality of the prefrontal lobes.

References Grimaud-Herv´e D. 1997. L’´evolution de l’enc´ephale chez Homo erectus et Homo sapiens: Exemples de L’Asie et de L’Europe. Les Cahiers de Pal´eoanthropologie. Paris: CNRS Editions. Heim JL. 1970. L’encephale neandertalien de l’homme de La Ferrassie. L’Anthropol 74 :527–572.

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Figure 117. Endocranial views (scale = 1 cm).

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LA FERRASSIE

Figure 118. Stipple drawing accenting the meningeal pattern (scale = 1 cm).

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see, but we believe the right lateral sinus shows inflow from the sagittal sinus.

LA QUINA V

Morphometric Data The left chord length, frontal to occipital poles, is 180 mm; the right side is 181 mm. The left lateral arc is 226 mm; the right side is 225 mm. The left dorsal arc length is ca. 232 mm; the right side is ca. 235 mm. The maximum chord breadth is 134 mm; the arc breadth is ca. 220 mm. The bregma-deepest cerebellum is ca. 135 mm. The bregma-lambda chord length is 103 mm; the arc is 107 mm. Neither the bregma-basion nor the maximum height can be measured on our cast. The biasterionic chord breadth is ca. 95 mm; the lateral arc over transverse sinuses is ca. 110 mm. The left bregmaasterion chord is 123 mm; the right side is 124 mm. The left lateral arc is 153 mm; the right arc is 154 mm. The maximum cerebellar width is ca. 95 mm and ca. 105 mm between sigmoid sinuses.

Gross Description La Quina V is a quite small (female?) endocranial cast lacking the entire base but preserving the remaining dorsal surface, including most of the cerebellar lobes.

Volume and Method It is the smallest of Western European Middle Paleolithic morphs, as its volume has been published as 1172 ml. (Anthony, 1913). The reliability is X1.

Endocast Details There is a slight left occipital petalia in length and width. There is a small right frontal petalia, suggesting a right-handed hominid. The left Broca’s cap region shows more lateral protrusion, while the right side appears more inferiorly displaced. The sulcal morphology is not clear enough to differentiate the parts of Broca’s cap region. The occipital lobes are rounded and protrusive, contributing to the occipital “bunning” common in these hominids. Well posterior to the lambdoid suture is a definite broad groove that may reflect the dorsal margin of the lunate sulcus. The sinuses are difficult to

Significance As the smallest of the Western European Middle Paleolithic morphs, this specimen is useful for extending our knowledge of size variation, and it gives us some indication of the degree of sexual dimorphism in these hominids.

Reference

The Human Fossil Record, Volume 3, by Ralph L. Holloway, Douglas C. Broadfield, and Michael S. Yuan. C 2004 John Wiley & Sons, Inc. ISBN 0-471-41823-4 Copyright


Anthony R. 1913. L’enc´ephale de l’homme fossile de La Quina. Bull M´em Soc d’Anthropol Par´ıs March 6:117–194.

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LA QUINA

Figure 119. Endocranial views (scale = 1 cm).

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Figure 120. Stipple drawing accenting the meningeal pattern (scale = 1 cm).

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Lazaret

Gross Description

Morphometric Data

Endocranial cast is of the right parietal bone of a child, said to have had a meningeal tumor, and it is associated with an Acheulean tool industry (de Lumley and Piveteau, 1969).

We provide the following measurements in the belief that they might be useful in calculating an accurate range of endocranial volumes for this specimen. The bregma-lambda chord length is 110 mm, and the arc length is ca. 118 mm. The bregma-asterion chord length is ca. 125 mm; the arc length is ca. 141 mm. The lambda-asterion chord is 58 mm. The bregmastephanion chord length is ca. 62 mm, and the arc length is ca. 68 mm.

Volume and Method We are not aware of any calculated volume for this endocast fragment. The measurements suggest the volume to be between 1200 and 1300 ml.

Significance

Endocast Details

Given the late Rissian, Middle Pleistocene age, this could be an early representative of the Neanderthal and La Chapelle morphs. It would thus be a valuable addition to sampling for this group.

Very little can be said regarding cortical morphology except that the lower parietal lobule shows a strong rounded contour of the angular gyral region, indicating that parietal lobe bossing occurred in a rather inferior position. The superior temporal region just above the squamous suture suggests a high degree of convolutional detail. The anterior and ascending branch of the middle meningeal vessels is strongly marked, and there is a large ascending branch of the posterior limb of the middle meningeal.

Reference de Lumley MA, Piveteau J. 1969. Les restes humains de la grotte du Lazaret (Nice, Alpes-Maritimes). M´em Soc Pr´ehist Franc¸ais 7:223–232.

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Figure 121. Endocranial view (scale = 1 cm).

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References

The best description of this endocast is provided by Grimaud-Herv´e (1997). RLH examined a cast while in France, but regarded it as very difficult to study because of its incomplete state and probable distortion. The right occipital region appears slightly more projective both in length and width, but this could be due to distortion. The left frontal appears slightly wider than the right. There appears to be a conflict regarding cranial capacity. Grimaud-Herv´e gives a capacity of 1650 ml, while Holloway’s (2000) Table 1 shows a capacity of 1352 ml. We do not have photographs of this specimen.

Grimaud-Herv´e D. 1997. L’´evolution de l’enc´ephale chez Homo erectus et Homo sapiens: Exemples de L’Asie et de L’Europe. Les Cahiers de Pal´eoanthropologie. Paris: CNRS Editions. Holloway RL. 2000. Brain. In: Delson E, Tattersall I, Van Couvering J, Brooks AS, eds, Encyclopedia of Human Evolution and Prehistory, 2nd ed. New York: Garland, pp 141– 149.

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Figure 122. Stipple drawings accenting the meningeal pattern (scale = 1 cm).

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Les Cott´es

There is a left occipital petalia, both in length and width, with a right frontal petalia, laterally.

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Monte Circeo

Gross Description

(a physical, virtual endocasts, and a Stereolithic model), Recheis et al (1999) have suggested a volume of ca. 1350 ml. A volume of 1376 ml was obtained after plasticene was added to the left pitted frontal and parietal regions and an inferior cerebellar portion reconstructed. Then, subtracting approximately 15 cc for the inflated right inferior orbital frontal gave a volume estimate of 1360 ml. The reliability is A1, given the lack of distortion and the completeness of the endocast. This value is assumed to be accurate, provided that the plastic whole endocast is not affected by shrinkage.

This endocast was kindly provided to RLH by Dr. Luca Bondioli, and we are most grateful for the opportunity to describe it. The endocast is nearly complete and undistorted. Missing are the inferior aspects of the cerebellar lobes, and the foramen magnum region to roughly the mid-clivus level. The inferior orbital region and lateral inferior portion of the right frontal lobe are also missing. Adherent matrix remains in the region of left lateral surface of the frontal lobe, as well as a small 4 by 4 cm portion of the left parietal lobe. There is a very strong left occipital petalia, both in posterior length and width, and the right frontal, appear wider than the left, even with the missing left frontal surface. The endocast is low, broad, and the width is greatest on the superior temporal lobes. While there is very little damage to the internal table of bone of the cranium, the brain endocast surface does not show any strong gyral or sulcal markings, including the Broca’s cap regions. The prefrontal portion of the frontal lobe is not sloping, the anterior portion being vertically oriented. There is a distinct prelambdoidal depression. The occipital lobes project very strongly over the cerebellar lobes.

Endocast Details There is a strong left occipital-right frontal petalial pattern, suggesting right-handedness. It is the strongest asymmetry we have seen in members of this morph from the Middle Paleolithic. Although there are no distinct sulcal markings on the endocast, the left occipital region strongly indicates the presence of a lunate sulcus by more than 10 mm posterior to the lambdoid suture, since there is a puckered appearance in that region. The superior temporal gyrus appears strongly protuberant to us. The basal portion of the endocast includes good detail of the pituitary fossa and cranial nerves on the left side. The details of transverse and sigmoid sinuses are not clear, but it appears that the right transverse sinus crosses the occipital pole region, rather than being in the midsagittal plane. In this respect the occipital region’s morphology appears unusual.

Volume and Method Originally, Sergi (1974) had determined a volume of ca. 1550 ml. Using different methods The Human Fossil Record, Volume 3, by Ralph L. Holloway, Douglas C. Broadfield, and Michael S. Yuan. C 2004 John Wiley & Sons, Inc. ISBN 0-471-41823-4 Copyright


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MONTE CIRCEO

Morphometric Data The left frontal pole to occipital pole chord is 177 mm. The right chord length is 172 mm. The left lateral arc length is 240 mm; the right side is 232 mm. The left dorsal arc length is 230 mm; the right side is 230 mm. The maximum chord breadth at the level of the midtemporal lobes is 144 mm, and the dorsal arc length between these points is 240 mm. The bregmabasion is ca. 120 mm, and the deepest temporal lobe to the vertex chord is 113 mm. The bregma-lambda cord is ca. 108 mm, and the arc is ca. 115 mm. The bregma to left asterion is ca. 128 mm, and the right side is 126 mm; the left arc length is ca. 155 mm, and the right arc length is ca. 158 mm. The maximum chord width across the cerebellar lobes is 104 mm, and 112 mm across the sigmoid sinuses. The cerebellar length is ca. 63 mm; the height is estimated at ca. 30 mm, and the cerebellar width at ca. 52 mm.

Significance The relative completeness and lack of distortion make this an important endocast specimen from this time

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period of Europe. Only minimal plasticene additions were needed to make it whole, thus enabling an accurate endocranial volume. The occipital morphology is unusual, and the base portion provides excellent morphological details that are missing in the other brain endocasts belonging to this morph from the Middle Paleolithic of Europe. The prefrontal lobe, with its vertical orientation, as well as broadness, indicates a morphology indistinguishable from modern humans, thereby suggesting behavioral equivalence with our own species.

Reference Sergi, S. 1974 IL Cranio Neandertaliano del Monte Circeo (Circeo I). Rome: Accademia Nazionale dei Lincei. Recheis, W. et al (1999) Re-evaluation of the Endocranial Volume of the Guattari 1 Neandertal Specimen (Monte Circeo). Coll. Antropol. 23:397–405.

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Figure 123. Endocranial views (scale = 1 cm).

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Podkumak

There exists the frontal portion only, with a clear right frontal petalia in anterior projection, and perhaps slightly wider on the right side.

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Predmost´i

During the early 1980s RLH had the opportunity to visit the British Museum of Natural History, London, and the Musee Histoire Naturelle and Musee de l’Homme in Paris. The descriptions that follow are from those visits and are mainly concerned with cerebral asymmetries of the endocasts of prehistoric moderns. We offer these observations here to indicate that the Upper Paleolithic hominids show exactly the same kinds of cerebral asymmetries that we find in extant humans, namely ourselves. Fuller descriptions of these are found in Grimaud-Herv´e (1997).

PREDMOSTI´ 4 There is a definite left occipital petalia both in length and width. Frontal widths appeared to RLH as almost equal, the right possibly just slightly larger in width than the left. The Broca’s cap regions are damaged and/or missing. The cranial capacity is given as 1250 ml.

PREDMOSTI´ 9 PREDMOSTI´ 3

The occipital petalias appear equal in length, but the true striate cortical region is slightly longer on the left side. The right occipital region appears slightly wider than the left; the right frontal petalia is wider than the left, but only slightly so. The Broca’s cap regions are incomplete. The cranial capacity is given as 1555 ml. (see accompanying figure, which shows the meningeal patterns depicted in Grimaud-Herv´e, 1997).

This endocast appeared to have a definite left occipital petalia, both in posterior and lateral projection to RLH, but the diagram of the superior view shown by Grimaud-Herv´e (1997) suggests that it is the right occipital lobe, which is wider. RLH observed a larger left frontal lobe, and that also appears on Grimaud-Herv´e’s Figure 98 (p. 307). The Broca’s caps are missing or damaged. The cranial capacity is given as 1580 ml.

PREDMOSTI´ 10

The Human Fossil Record, Volume 3, by Ralph L. Holloway, Douglas C. Broadfield, and Michael S. Yuan. C 2004 John Wiley & Sons, Inc. ISBN 0-471-41823-4 Copyright


This endocast shows one of the most extreme degrees of a left occipital petalia, both in posterior projection

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P R E D M O S T ´I

and width, combined with a strong right frontal width petalia, also in both lateral and length projections. The longitudinal sinus goes to the right lateral sinus. The Broca’s cap is damaged (missing on the left), so asymmetry in this region cannot be described. The cranial capacity is given as 1452 ml.

Significance The Predmost´ı endocasts show essentially extant human characteristics, although the Broca’s cap regions are

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missing. In particular, these endocasts show the normal range of cranial capacities and endocranial shape, with cerebral heights significantly higher than in morphs similar to Gibraltar and La Chapelle.

Reference Grimaud-Herv´e D. 1997. L’evolution de l’enc´ephale chez Homo erectus et Homo sapiens: Exemples de L’Asie et de L’Europe. Les Cahiers de pal´eoanthropologie. Paris: CNRS Editions.

Figure 124. Predmost´ı 3 (not to scale).

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Figure 125. Predmost´ı 4 (not to scale).

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P R E D M O S T ´I

Figure 126. Predmost´ı 9 (not to scale).

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Figure 127. Predmost´ı 9. Stipple drawing accenting the meningeal pattern (not to scale).

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P R E D M O S T ´I

Figure 128. Predmost´ı 10 (not to scale).

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Figure 129. Predmost´ı 10. Stipple drawing accenting the meningeal pattern (not to scale).

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Reilingen

Gross Description

rostral to the occipital pole, the medial end of this purported lunate sulcus shifts in a rostral direction and continues another 20 mm. This is probably the occipitalis transversalis sulcus leading into a rostrad directed paraoccipitalis sulcus; however, the latter is poorly defined.

Missing are the entire frontal lobe and base, portions of both cerebellar lobes, brain stem, and temporal poles. There is good preservation of internal table of bone, and no distortion.

Parts of the lateral calcarine are suggested by Yshaped sulci. The interparietal groove is tortuous. The overall impression of the pattern is that it is of a wholly modern human. The confluens appears to flow into the left transverse sinus. The meningeal patterns are easily traced and show a pattern typical of specimens such as Arago and Swanscombe, as seen in Dean et al., (1998: Fig 4, p. 501), showing a dominant posterior branch of the middle meningeal vessel.

Volume and Method RLH in Dean et al. (1998) found a volume of 1430 ml, based on a full plasticene reconstruction of the missing parts and the water displacement method. The reliability is A1.

Endocast Details There is a large left occipital petalia, but without the frontal lobes we cannot assess the handedness from the occipital lobes alone. The lower limb of the left postcentral gyrus shows a strong postcentralis transversus and a postcentralis inferioris, which lie some 30 to 40 mm posterior to the coronal suture. There are two faint grooves that are probably marginal and angular gyri of the parietal lobe. We quote RLH’s (Dean et al., 1998: 499–500) description of the occipital lobe:

Morphometric Data The estimated maximum chord length from frontal to occipital poles is 171 mm. The dorsal arc is ca. 205 mm, including frontal reconstruction. The lateral arc length is ca. 225 mm. The maximum chord breadth is 138 mm, and the arc breadth length is ca. 235 mm. The bregma to basion is ca. 133 to 136 mm, and the maximum height is 120 mm. The bregma-deepest cerebellum is ca. 135 mm. The chord length of bregma to lambda is 103 mm and the arc length is 110 mm. The bregma-asterion (lft) chord is ca. 124 mm, and the arc is ca. 153 mm. The widest cerebellar breadth is ca. 112 mm, and between the sigmoid sinuses it is estimated to be ca. 120 mm.

There is a somewhat crescentic sulcus roughly 15 mm rostral to the occipital pole. Although there is a slightly concave interruption posteriorly, it would appear to be a typical modern lunate sulcus. . . . At roughly 16 mm The Human Fossil Record, Volume 3, by Ralph L. Holloway, Douglas C. Broadfield, and Michael S. Yuan. C 2004 John Wiley & Sons, Inc. ISBN 0-471-41823-4 Copyright


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Significance Dean et al. (1998) suggested this cranium should be assigned to a stage 2 “pre-Neanderthal” group such as Steinheim, Swanscombe, and Atapuerca (SH site). The brain endocast suggests a suite of modern human features, despite the pentagonal shape when viewed from the occipital bone, such as the large volume, left occipital petalia, and modern convolutional pattern.

Reference Dean D, Hublein J-J, Holloway RL, Ziegler R. 1998. On the phylogenetic position of the pre-Neandertal specimen from Reilingen, Germany. J Hum Evol 34:485–508.

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REILINGEN

Figure 130. Endocranial views (scale = 1 cm).

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Spy

Gross Description

(1975) provides an estimate of 1300 ml, which we believe is more accurate.

Spy 1 Spy 1 is mostly complete and undistorted in its dorsal half. Missing are the left frontal lobe and the Broca’s cap region on both sides, as well as most of the basal portion, including the medial and anterior portions of the temporal lobes, brain stem, foramen magnum region, and inferior cerebellar lobes.

Spy 2 Holloway (1981) found an endocranial volume of 1553 ml, larger than the 1425 ml volume given by Coon (1962) and the 1504 ml volume by Thoma (1975). The method used was water displacement, and the reliability is A1.

Spy 2 Spy 2 is more complete than Spy 1. It is missing less of the frontal orbital region, but unfortunately, it is lacking both of the Broca’s cap regions, the middle temporal poles, brain stem, foramen magnum region, and portions of the posterior cerebellar lobes. The endocast appears undistorted, and larger than Spy 1 yet retains the platycephalic shape characteristically seen in other Western European morphs from this time period.

Endocast Details Spy 1 The Spy 1 endocast is long, low, and broad, as other endocasts from the Middle Paleolithic of Western Europe. There is a definite left occipital petalia, both in length and width and a right frontal petalia in width. There is some occipital bunning, and a small, shallow delimiting groove posterior to the lambdoid sutural remnant on the left side that could feasibly be the dorsal limit of the lunate sulcus. The sagittal sinus appears to flow left into the transverse sinus. The meningeal vessels are not very clearly imprinted on the endocast’s surface.

Volume and Method Spy 1 Holloway (1981) found a volume of 1305 ml, based on his completed reconstruction and water displacement technique. The reliability is A1. Coon (1962) had reported a volume of 1525 ml, and von Koenigswald (1976) reported a volume of 1562 ml, whereas Thoma

Spy 2 There is a very large left occipital petalia, in both length and width, and a clear right frontal petalia in width. The prefrontal region is full and rounded as in modern humans. Posterior to the lambdoid suture is a limiting groove on both occipital lobes that may be the dorsal boundary of the lunate sulcus. The left occipital

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lobe also has a limiting sulcus above the transverse sinus which could be interpreted as the lateral margin of the lunate sulcus. Alternatively, this is some process caused by the “bunning.” We do not see any readily identifiable convolutions on the parietal lobes, although the posterior temporal and inferior parietal region appears voluminous on both sides. The right transverse sinus receives most of the sagittal sinus flow. The middle meningeal vessels are well represented on both sides.

across the transverse sinuses is ca. 112 mm. The dorsal arc is ca. 190 mm. The bregma-asterion chord length, left side, is 129 mm; the arc length is 156 mm. The right side, respectively, is 131 mm and 168 mm. The maximum cerebellar width across the sigmoid sinuses is 120 mm.

Significance Spy 1

Morphometric Data Spy 1 The left maximum chord length between frontal and occipital poles is 176 mm; the right side is 175 mm. The left lateral arc length is ca. 224 mm; the right side is ca. 228 mm. The left dorsal arc length is ca. 235 mm; the right side is 235 mm. The maximum chord breadth is 136 mm; the arc breadth is ca. 220 mm. The bregmabasion chord length is ca. 120 mm; the maximum height is ca. 113 mm. The bregma-lambda chord is ca. 105 mm; the arc length is ca. 110 mm. The biasterionic chord breadth is ca. 105 to 110 mm; the arc length is ca. 120 mm. The bregma-asterion chord, left side, is ca. 122 mm, and the arc length is ca. 140 mm; the right side chord is ca. 125 mm, and the arc length is ca. 155 to 160 mm. The maximum cerebellar width (sigmoid sinuses) is ca. 118 mm.

Spy 2 The maximum chord length, left side, between frontal and occipital poles is 180 mm; the right side is 179 mm. The lateral arc length, left side, is 237 mm; the right side is 230 mm. The dorsal arc length, left side, is 246 mm; the right side is 246 mm. The maximum chord breadth is 141 mm; the arc breadth is 240 mm. The bregmabasion chord length is ca. 132 mm; the maximum height over the vertex is 115 to 120 mm. The bregma-lambda chord length is 101 mm; the arc length is 106 mm. The biasterionic chord breadth is 104 mm; the arc length

This endocast is the smaller of the two Spy hominids, and suggests a female. The morphology is quite similar in overall shape and asymmetry features as in most Western European morphs from the Middle Paleolithic (currently assigned to H. neanderthalensis) brain endocasts.

Spy 2 As the larger of the two Spy specimens, it is most probable that this specimen was a male, thus providing some information regarding possible sexual dimorphism. As with the other Western European Middle Paleolithic morphs, the combination of asymmetries and rounded prefrontal regions suggests a morphological condition most similar to that of modern humans.

References Coon CS, 1962. The Origin of Races. New York: Knopf. Holloway RL. 1981. Volumetric and asymmetry determinations on recent hominid endocasts: Spy I and II, Djebel Ihroud I, and the Sale Homo erectus specimens, with some notes on Neanderthal brain size. Am J Phys Anthropol 55:385–393. Thoma A. 1975. Were the Spy fossils evolutionary intermediates between classic Neanderthal and modern man? J Hum Evol 4:387–410. von Koenigswald GHR. 1976. The Evolution of Man, rev ed. Ann Arbor: University of Michigan Press.

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Figure 131. Spy 1 (scale = 1 cm).

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Figure 132. Spy 2 (scale = 1 cm).

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Swanscombe

Gross Description

preting the convolutional pattern, except to conclude that the Swanscombe brain endocast fell within the range of features known for modern Homo sapiens. He too (see infra) was struck by the complexity of detail in the occipital lobes, as well as the inferior parietal lobule of the parietal lobe. The occipital lobe morphology is very complex, and we regard LeGros Clark’s (1938) identification of “b” rather than “a” as the lunate sulcus reasonable. The meningeal patterns show an extensive ramification of the middle and posterior branches of the middle meningeal vessel, and a large contribution from the posterior branch.

Swanscombe is a nearly complete and undistorted brain endocast, missing the entire frontal lobe, and middle and inferior parts of the temporal lobes.

Volume and Method The published value for the endocranial volume is 1325 ml (Mourant, 1938). This value was based on calculations from arc and chord measurements. We have not independently confirmed this value but are in the process of making a total brain endocast reconstruction. We regard the reliability as X2.

Morphometric Data Endocast Details

The maximum chord breadth is 140 mm, and the arc breadth over the vertex is 236 mm. The bregma-lambda chord is 101 mm, and the arc is 108 mm. The bregmaasterion chord, left side, is 123 mm, and the arc is 145 mm; on the right side these are 124 mm and 146 mm, respectively. The biasterionic breadth chord is ca. 112 mm, and the lateral arc across the transverse sinus is ca. 130 mm. The dorsal biasterionic arc is ca. 170 mm. We estimate the maximum cerebellar width as ca. 120 to 125 mm. The bregma-basion chord length is ca. 135 mm.

This brain endocast shows a very great amount of convolutional detail. There is a small left occipital petalia in length, but the right width is larger. With the frontal lobes missing we cannot assess the frontal petalial pattern. The sagittal keeling is distinctive. The confluens drains primarily to the left transverse sinus, which is particularly large in this hominid. The lambdoid suture is well anterior to any delineation of the occipital lobes that might be interpreted as a lunate sulcus. LeGros Clark (1938) did the original endocranial description. He exercised the greatest caution in inter-

Significance

The Human Fossil Record, Volume 3, by Ralph L. Holloway, Douglas C. Broadfield, and Michael S. Yuan. C 2004 John Wiley & Sons, Inc. ISBN 0-471-41823-4 Copyright


This is perhaps the finest brain endocast for all of Middle Pleistocene Western Europe in terms of lack of dis-

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tortion and convolutional detail, indicating that a large brain size had been achieved by this time, some 0.2 to 0.25 MYA.

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Reference Clark WE LeGros. 1938. The endocranial cast of the Swanscombe skull bones. J R Anthropol Inst 68:61–67.

Figure 133. Endocranial views (scale = 1 cm).

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Figure 134. Stipple drawing accenting the meningeal pattern (not to scale).

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Endocranial Vasculature by Dominique Grimaud-Herve´ Illustrations by Pascal Herve´

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Meningel Patterns

(2) the middle meningeal system, which corresponds to the parieto-temporal region and a portion of the anterior occipital region, and (3), the cerebellar region, which is comprised of a small, difficult to observe system within the cerebellar fossa. Of these three systems the middle meningeal system is the one that appears to have undergone the greatest alteration during hominid evolution. The meningeal vascular system is complex in that each principal branch gives rise to numerous other branches that eventually anastomose with adjacent vessels, creating an intricate vascular net. Over the last century several researchers have attempted to identify and name the various branches and branching pattern of this system, occasionally resulting in little continuity between studies (e.g., Giuffrida-Ruggieri, 1913; Asachi and Hasebe, 1928; Bazocchi, 1933; Marcozzi, 1942). With regard to the work that has been done on endocasts, we prefer the terminology of Saban (1977, 1984, 1986, 1995). During the course of human development the increasing complexity of the meningeal system mirrors that of the brain and skull with rapid growth occurring after birth and continuing up to early adulthood. In general, the meningeal system reaches adult proportions by about the seventh postnatal year. For example, Saban (1984) observed an increase in the arborization of the three principal branches of the middle meningeal artery (i.e., anterior or bregmatic, middle or obelic, and posterior or lambdatic) during the first postnatal year with subsequent augmentation of the number of anastomoses between these branches.

On the endocranial surface of the skull one can observe vascular grooves that arise from foramina in the skull base and ascend toward the vertex. These grooves are the product of meningeal vessels (i.e., meningeal arteries and their accompanying veins), which act to supply blood to the calvaria and dura mater (Saban, 1995). However, while one would suspect that the meningeal vessels represent the principal blood supply to the meninges and little to the other surrounding tissue, this would be incorrect, as these vessels actually supply more blood to the calvaria than they do to the dura. As in modern humans, meningeal grooves are often visible on the endocranial surface and thus the endocast. Occasionally the preservation of this vascular network is so complete that it is possible to observe the small terminal branches. While the general components of this system have remained stable since the mid-Pliocene, there have been minor shifts in the branching pattern of the principal meningeal vessels (e.g., middle meningeal artery) over the past three million years (Saban, 1982, 1984, 1993, 1995). Thus the meningeal system can be a useful tool in understanding brain evolution within hominids. The study of the meningeal system can be reduced to three different regions: (1) the anterior meningeal system, which corresponds to the frontal region, The Human Fossil Record, Volume 3, by Ralph L. Holloway, Douglas C. Broadfield, and Michael S. Yuan. C 2004 John Wiley & Sons, Inc. ISBN 0-471-41823-4 Copyright


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The middle meningeal system, comprising one artery and two veins, exhibits some variation over the course of human evolution. For example, several characteristics concerning the development and the orientation of this network and have been observed simultaneously in Africa, Asia, on the one hand, and in Europe, on the other (Grimaud-Herv´e, 1997). Within mid- to late Homo (e.g., Homo erectus, Homo neanderthalensis, and Homo sapiens) the arteriovenous middle meningeal vascularization can be divided into several categories: Africa. The anterior branch of the middle meningeal system appears to be more developed on the African hominid endocasts. This branch is more prominent on KNM-WT 15000 (Begun and Walker, 1993) and KNM ER 3883. The anterior network has an obelic branch that shows an important development with increasing number of ramifications on Ternifine 4 (Saban

1984; Del Corso 1992) and a few anastomoses such as on Sal´e. These become more numerous on Kabwe, Jebel Irhoud 1 and 2, and Omo 2 (see Fig. 135 and individual site entries). Asia. The obelic or middle branch of the middle meningeal artery is well developed in all hominids of this region. This branch can be observed either to arise as a single prominent vessel, as is common in the Zhoukoudian endocasts, or to bifurcate a short distance from the origin of the middle branch, as is the case in several of the Trinil and Sangiran endocasts. In a third configuration as with most of the Ngandong endocasts, the obelic branch has a posterior contribution, but the anterior branch is often more developed (see Fig. 136 and the Ngandong entry). Europe. The anterior ramus, which only arises from the bregmatic branch, is as prominent as the posterior ramus in Pre-Neanderthals and Neanderthals (e.g.,

Figure 135. Middle meningeal system in African hominid fossils. A: KNM-WT 15000 (Begun and Walker, 1993); B: Sal´e; C: Jebel Irhoud 2 (not to scale).

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Figure 136. Middle meningeal system in Asian hominid fossils. A: Zhoukoudian Skull I, Locus L; B: Zhoukoudian Skull III, Locus E; C: Trinil 2; D: Sangiran 17; E: Ngandong 3; F: Ngandong 7 (not to scale). Arago, Le Moustier, Neanderthal, or La Chapelleaux-Saints). This anterior ramus, comprising an obelic branch, is more prominent in Swanscombe, Ehringdorf 9, Gibraltar 1 and 2, Teshik Tash 1, Engis 2, La Ferrassie 1, and La Quina H5 (see Fig. 137 and individual site entries).

In modern humans there is a notable dominance of the anterior and middle rami, while the lambdatic branch is much less developed. The branching pattern of the middle ramus is variable, continuing some distance as a prominent single unit, giving off minor branches along its path, or as two or more separate

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Figure 137. Middle meningeal system in European hominid fossils. A: Arago 21, 47; B: Swanscombe; C: La Ferrassie; D: Predmosti 9 (not to scale). branches that arise off the shortened middle ramus. This latter bifurcated pattern is present in Predmost 3, left hemisphere of Predmost 4, and Dolni Vestonice 1 and 2. In addition to the general branching pattern seen in particular hominid groups, one can also compare the orientation, extent of branching, and the general area served by the meningeal vessels. For example, in the Zhoukoudian endocasts the anterior middle meningeal system tends to serve only those regions anterior to the coronal suture, while in the Indonesian and European endocasts the anterior ramus sends branches both anterior and posteriorly. Conversely, the posterior ramus displays reduced branching over time. In earlier Homo (e.g., Zhoukoudian, Sangiran, Trinil, and Ngandong), it sends branches overlying the mid- to posterior parietal region. In later Homo the posterior sends limited branches to just the posterior parietal region (e.g.,

Swanscombe 1, Ehringsdorf 9, and all Homo neanderthalensis and Homo sapiens). This reduced vascular branching also appears to carry over to the degree of anastomotic points seen. Thus one sees more numerous anastomoses in the early Indonesian Homo erectus fossils than in later Homo erectus, Neanderthals, and modern humans, albeit the degree of anastomotic connects is more variable and difficult to accurately assess (Saban, 1993). Two other features of the meningeal system that bear mention are orientation and asymmetry. In general, as brain size increases, the orientation of the middle meningeal vessels changes from a more vertical placement to a more diagonal or posterior placement. In later Homo the branches sweep supero-posteriorly rather than traveling in the more superior direction as is the case in earlier hominids. In addition the vascular branching pattern appears to be asymmetrical, with one

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hemisphere exhibiting a more complex branching pattern versus the contralateral side. However, the meaning and overall degree of this branching is difficult to discern when it comes to meningeal vessels, unlike that of the cerebral venous sinuses.

Dural Venous Sinuses The dural sinuses occupy space between the periosteal and meningeal layers of the dura. The larger veins from the brain drain into these sinuses, which all ultimately drain into the internal jugular veins in modern humans. Few of the dural sinuses leave impressions on the endocranium; however, of the visible sinuses much has been said. The visible sinuses include the sphenoparietal, petrosquamous, superior sagittal, transverse, sigmoid, and the confluens. More rarely, though apparently more common in Paranthropus, are the occipital and marginal sinuses. The superior sagittal sinus is occasionally visible along its entire length. However, in most endocasts it tends to be only visible posteriorly in the occipital region as it drains toward the confluens. In most individuals the sagittal sinus will drain either entirely or preferentially toward either the left or right transverse sinus. As first noted by Smith (1907), this asymmetric drainage pattern has been suggested to correlate with the occipital petalial pattern, such that individuals with a left occipital petalia (ostensibly right-handers) will have prominent drainage of the sagittal sinus toward the right transverse sinus. Thus the right transverse sinus and right sigmoid sinus will be markedly more prominent that the left transverse and sigmoid sinuses. While the mode of drainage of the sinuses to the confluens and subsequently out to the transverse and sigmoid sinuses is a pattern seen in the Hominoidea, variations are present and even appear to be possibly unique to certain hominid groups. Most prominent and controversial among these is the occipital/marginal drainage pattern championed by Falk and Conroy (1983) present in many robust hominids. In this case the confluens drains prominently into the occipital sinus, which travels between the cerebellar hemispheres, draining into the paired marginal sinuses, which travel lateral to the foramen magnum and ultimately into the jugular foramen or the sigmoid sinus. This unique variant is most prominent on endocasts of the robust clade such as OH 5. However, the uniqueness of the feature in robust morphs (Paranthropus) appears disputable (see

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Kimbel, 1984) and is not a synapomorphy of robust morphs (Paranthropus) (e.g., Konso; see also Holloway et al., 2002).

Sphenoparietal Sinus The sphenoparietal sinus, which occupies a strip just posterior to the coronal suture, has been frequently noted. While noticeable in some Homo erectus and Neanderthal endocasts, it is less developed in modern humans, being observable in only 14% of modern human endocasts. For example, it can be observed on Trinil 2, Sangiran (2, 10, 12), and Zhoukoudian (III, X, XI, XII) endocasts, albeit the feature is not strong. Conversely, it has never been observed on the more recent Ngandong population. As for Neanderthal, this sinus is observable in the Ehringsdorf 9, La Quina H5, Le Moustier, Teshik Tash, and La Ferrassie 1 endocasts, and is relatively prominent on the endocasts of Neanderthal and La Chapelle aux Saints (see Fig. 138).

Petrosquamous Sinus The petrosquamous sinus travels along the petrosquamous suture, connecting the transverse sinus with the ipsilateral middle meningeal vein. Its presence is variable in adult modern humans (about 30%), and it is noticeable in some fossil endocasts such as Homo habilis (Saban, 1984), Homo erectus, and Homo neanderthalensis.

Confluence of Sinuses (Confluens) Situated at the level of the internal occipital protuberance, the confluens represents the drainage convergence of six of the dural sinuses. The prominence and precise point of the confluens is variable in modern humans, being either symmetrical or asymmetrical in appearance (Testut, 1911, Delmas and Chifflet, 1950). In modern humans, as with most fossil endocasts, the confluens is generally asymmetrical, as the sagittal sinus tends to drain primarily to the left or right transverse sinus with rightward drainage being most common (e.g., 85% in H. erectus and Neanderthal, and 80% in modern humans) (see Fig. 139).

Significance of Endocranial Vasculature As with cranial capacity, the features associated with dural vasculature have altered over the course of human evolution. In general, there has been an increase in the complexity of the branching pattern of the anterior ramus of the middle meningeal vessels. Conversely, there

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Figure 138. Sphenoparietal sinus. A: Sal´e; B: Jebel Irhoud I; C: Zhoukoudian Skull I, Locus L; D: Ngandong 11; E: Ehringsdorf 9; F: La Ferrassie; G: Predmosti 10 (not to scale).

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Figure 139. Posterior confluence of sinuses. A: Jebel Irhoud 1; B: Trinil 2; C: Ngandong 6; D: Biache-Saint-Vaast 1; E: Dolni Vestonice 2 (not to scale).

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has been a general reduction in the complexity of the branching pattern of the posterior ramus of these same vessels. This was possibly due to an increase in cranial capacity and alteration in the overall shape of the endocranium. For the dural sinuses there has been a reduction in the prominence of the petrosquamous and sphenoparietal sinuses from H. erectus to modern humans. In addition the flow of the sagittal sinus to either the left or right transverse sinus is more consistent once one reaches H. erectus. However, the possible cause or function of the drainage pattern is uncertain. For example, Smith (1907) suggested that the asymmetrical flow of the sagittal sinus to the right transverse sinus (normally in right-handers) might be responsible for producing a left occipital petalia. This, though, was an admitted speculation on Smith’s part, and one can only guess if the asymmetrical drainage of the sagittal sinus into the transverse is responsible for a contralateral petalia, if the reverse is true, or if the two features are developmentally mutually exclusive. During hominid evolution, several characteristics have been observed to occur almost simultaneously: 1. Reduction of the presence of petrosquamous and sphenoparietal sinuses. 2. An increase in the development of the anterior ramus of the middle meningeal system, associated with a definite decrease of the posterior ramus. 3. Encephalic surface increasingly covered by this anterior network, which, while located on the precentral gyrus in early hominids endocasts, extends onto the parietal lobe of modern Homo. 4. Increasing ramifications and anastomoses, constituting an increasingly dense and tight patterning on African fossils hominids, anatomically modern and extant Homo. The more recent fossil hominids, in Asia (Homo erectus from Ngandong) as well as in Europe (Homo neanderthalensis), show reduction of the middle meningeal system. Can the middle meningeal reduction associated with those two fossil hominid groups be correlated with a parallel evolutionary change? In the earliest hominids the vascularization has a distinctly vertical orientation. Through time this orientation becomes oblique and may be associated with occipital rounding. Thus early Homo erectus, with an endocranial volume of 800 to 900 ml, shows a slight predominance of the anterior network. It is slightly different from Homo erectus (sensu

stricto) with this anterior ramus development (Begun and Walker, 1993), but the general orientation and the poor vascularization are characters common to these two groups. Asiatic Homo erectus (sensu stricto), with cranial capacities between 800 and 1200 ml, are characterized by a middle meningeal system in which the three branches are represented: the posterior one, comprising an obelic branch, is generally more developed. The persistence of the petrosquamous portion has been noted on the majority of fossil hominid endocasts in this group. The sphenoparietal imprint, when it is present, is very slight. Archaic Homo sapiens, with endocranial capacities between roughly 900 and 1300 ml, are distinguished by an important development of the anterior ramus. This ramus, which is nearly equivalent to the posterior ramus on African Homo ergaster (KNM-WT 15000), becomes increasingly predominant through time with specimens such as Ternifine 4 and Kabwe (archaic Homo sapiens). We note an increasing number of ramifications and anastomoses, which are going to constitute a real vascular network on the most recent fossil hominids. Homo neanderthalensis, whose endocranial volumes are near to 1550 ml, are endowed with an especially large sphenoparietal sinus. The sphenoparietal sinus is observed without exception on all the specimens from this group. The middle meningeal system is much reduced, poorly developed with minor ramifications and practically nonexistent anastomoses. Nevertheless, the anterior branch is predominant. Homo sapiens, with an average cranial capacity of 1410 ml, shows great development of the middle meningeal system, with an increase of the number of ramifications and an important increase of the anastomoses. Primarily located in the superior part of the cranial vault, the anastomoses extend over the total parietal surface becoming an elaborate plexus, and the multiplication of anastomoses reaches the temporal region. The vascular plexus has realized its maximal density, and is thus similar to that of extant Homo (Saban 1984). The anterior ramus, comprising the ramified obelic branch, is particularly well developed. It covers almost the total parietal lobe surface including the posterior frontal and the anterior occipital regions. As for lambdatic branch, it is reduced to a single vessel. Is it meaningful to correlate the anterior middle meningeal system development with the possibility that a better draining brain was a better performing brain? It appears undeniable that important cultural stages have been accomplished among the different fossils

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hominids from Africa, Asia, and Europe. It seems counterintuitive to discover that Ngandong and Neanderthal populations (i.e., the more recent hominids with supposedly more advanced technologies) show reduced vascular systems in terms of number of ramifications and anastomoses. We cannot deny that Neanderthal culture is much better known than that for the Ngandong hominids, and that their cultural stage was more complex than that of their predecessors, such as Arago, which shows a relatively more developed meningeal vascularization pattern. These hominids are characterized by the appearance of a new technology called the Levalloisian, a more elaborate stone tool industry. Neanderthals are also associated with burials, suggesting, but not proving, a concern with a possible afterlife. In short, this cultural evolution is associated with fossils hominids whose middle meningeal vascularization shows an anterior branch relatively much less developed than that of their predecessors. This pattern is observed on Arago 47 and Swanscombe (GrimaudHerv´e, 1997) and on hominids from Sima del Huesos, Spain (Gracia, 1991, personal communication). In Africa, however, the vascular network is becoming more developed through time from KNM-WT 15000 to the most recent fossils hominids. This vascular augmentation is concomitant with an increase in cultural complexity. Similarly, in anatomically modern Homo sapiens, the middle meningeal network is the most developed with a more dense and tight patterning of their endocast surface, and they show cultural acquisitions such as the appearance of artistic manifestations (parietal painting, sculpture, and engraving) and with burials that are much more elaborate, suggesting fright and a preoccupation of the and its metaphysical elaboration. Thus these new cultural attainments from Homo neanderthalensis and the last Homo erectus, on the one hand, and African fossil hominids, anatomically modern, and extant Homo, on the other hand, show opposite vascular patterns. The first pattern becomes poorer and is certainly cannot be an indication of better blood circulation to the meninges and inner table of cranial bone, while the second pattern is undergoing maximal development. We remain uncertain as to the actual blood circulation to the brain itself, thanks to the opacity of the meninges in real life. Consequently this discrepancy allows us to conclude that the cultural development of hominids does not correlate in any significant way with the development of the middle meningeal system.

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References Asachi B, Hasebe K. 1928. Das arteriensystem der Japanern, Kyoto, Kais, Jap. Univ, I Act Sch Med Univ Imp Kyoto 9:9–102. Bazzochi C. 1933. Sui Solchi andocranini della arteriameningea media nei crani con “canalis infrasquamosus.” Riv Anthropol 30:223–234. Begun D, Walker AC. 1993. The endocast. In: Walker, AC and Leakey RE, eds, The Nariokotome Homo erectus Skeleton. Cambridge: Harvard University Press, pp 326– 358. del Corso M. 1992. Le moulage endocrˆanien de Sal´e (Maroc). Etude des proportions et contours de l’endocrˆane en vue d’une d´efinition biom´etrique a` but syst´ematique. DEA de l’Universit´e de Montpellier II, 33 pp, 116 pp d’annexes. Delmas A, Chifflet J. 1950. Le pressoir d’H´erophile. C R Ass Anat 37:123–131. Falk D, Conroy GC. 1983. The cranial venous sinus system in Australopithecus afarensis. Nature 306:779–781. Giuffrida-Ruggeri V. 1913. Variabilita delle remificazioni terminali dell arteria meningeo media nell’uomo. Giubilare in onore di L.Bianchi, 7 pp. Gracia A, Arsuaga JL, Martinez I. 1992. Los restos humanos craneales de Cova Negra, Valencia. Rev Esp Paleontol extra:77–81. Grimaud-Herv´e D. 1997. Evolution de l’enc´ephale chez Homo erectus et Homo sapiens. Les Cahiers de Pal´eoanthropologie. Paris: CNRS Eds. Holloway RL, Yuan MS, Broadfield DC, DeGusta D, Richards GD, Silvers A, Shapiro JS, White TD. 2002. The missing Omo L338y-6 occipital marginal sinus drainage pattern: Ground sectioning, CT scanning, and the original fossil fail to show it. Anat Rec 266:249– 257. Kimbel WH. 1984. Variation in the pattern of cranial venous sinuses and hominid phylogeny. Am J Phys Anthropol 63:243–263. Marcozzi V. 1942. L’arteria meningea negli nomini recenti, nel Sinantropo, e nelle Scimmie. Riv Antropol 34:407– 436. Saban R. 1977. Evolution du r´eseau des veines m´ening´ees moyennes chez les primates, d’apr`es les empreintes pari´etales endocrˆaniennes. CR Acad Sci 285:1451– 1454. Saban R. 1982. Les empreintes endocrˆaniennes des veines m´ening´ees moyennes et les e´ tapes de l’´evolution humaine. Ann Pal´eontol Hum (Vert-Invert) 68:171–220. Saban R. 1984. Anatomie et e´ volution des veines m´ening´ees chez les hommes fossiles. Paris: ENSB-CTSH Eds.

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Saban R. 1986. Les rapports des veines m´ening´ees moyennes avec la paroi endocrˆanienne chez l’homme, au cours de la croissance. Nova Acta Leopoldina 262:425– 437. Saban R. 1993. Aux sources du langage articul´e. Masson: Collection Pr´ehistoire. Saban R. 1995. Image of the human fossil brain: Endocranial

casts and meningeal vessels in young and adult subjects. In: Changeux J-P, Chavaillon J, eds, Origins of the Human Brain. Oxford: Clarendon Press, pp 11–38. Smith GE. 1907. A new typographical survey of the human cerebral cortex. J Anat Physiol 41:237–254. Testut L. 1911. Trait´e d’anatomie, Ang´eiologie, Syst`eme nerveux central, II. Masson, Paris 1096 pp.

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Mosaic Evolution Clearly, the evolution of the hominid brain has been a mosaic affair, at times punctuated, at other times gradual, with allometric and nonallometric brain size increases, interspersed (or interdigitated) with episodes of reorganization of the brain’s nuclei, fiber tracts and lobes (see Tables 1–2, Part I for a summary). We cannot know directly about much of the latter changes, particularly when they occur at the subcortical level. We must assume that the changes occurred during the evolution from an ape-like precursor, whose neuroanatomical relationships were somewhat similar to those of extant chimpanzees and gorillas. However, it is always imperative to remember that extant apes have their own individual lines of evolutionary development from time periods most probably situated within the last 5 to 10 million years. And while it is certainly true that the major external phenotypic effect we can witness from the treasures of the fossil record is an increase in brain size, the actual processes must surely have been much richer. The earliest evidence bearing on this mosaic evolution comes from the australopithecines from 3 to 4 MYA and, in particular, from A. afarensis. As fascinating as recent finds such as Sahelanthropus tchadensis, Kenyanthropus platyops, Ardipithecus ramidus, Australopithecus anamensis, or Orrorin tugenensis might be, these discoveries simply do not provide enough cranial material to allow an accurate determination of relationships with each other to ascertain which was the true stem ancestor to the hominid line eventually giving rise to Australopithecus and later Homo. We assume that the cranial capacity of such an ancestral group was in the size range of 300 to 400 ml, while the brain itself probably showed no lateral expansion or broadening of either prefrontal lobes nor any significant cerebral asymmetry in either occipital or frontal regions. That ancestral group most probably retained the sympleisomorphic condition of an enlarged primary visual striate cortex, with an anteriorly placed lunate sulcus, a condition clearly shown in Proconsul africanus by Radinsky (1974, 1975) and later by Falk (1983). Perhaps these predictions will be borne out with future discoveries. At a minimum, a well-preserved occipital bone might decide this issue once and for all, as we have seen from the Stw 505 specimen. The Human Fossil Record, Volume 3, by Ralph L. Holloway, Douglas C. Broadfield, and Michael S. Yuan. C 2004 John Wiley & Sons, Inc. ISBN 0-471-41823-4 Copyright


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Australopithecus afarensis, by contrast to the earliest taxa, possessed a somewhat larger brain, ranging from perhaps 385 ml to more than 550 ml (the latter in large males), with considerable sexual dimorphism in body size and thus brain size as well. While we cannot be certain regarding the full anatomy of the frontal lobe, it is unlikely that the Broca’s cap region was developed much beyond that of earlier apes. The present specimens, such as Hadar AL 444-2 or the child AL 333105, simply do not have a Homo-like disposition of this region. Nor can we be certain that cerebral asymmetries, perhaps reflecting handedness and possibly other hemispheric specializations underlying more complex cognitive processes, existed in this hominid. We are certain, however, based on the parietal and occipital fragments of the Hadar AL 162-28 specimen with excellent preservation of the internal table of bone that the lunate sulcus was in a more posterior position, thus reflecting a relative reduction of primary visual cortex, or area 17 of Brodmann (see Hadar, Figs. 1–2; Holloway, 1983a). Indeed, based on a comparison with over 70 chimpanzee brain hemispheres of roughly the same volume, the Hadar AL 162-28 fossil shows a distance between the posterior end of the interparietal sulcus and the occipital pole of 15.5 mm, which is roughly one-half the distance found in chimpanzee brains often smaller in brain volume. This distance is roughly 4 SD’s less than in chimpanzees (Holloway et al., 2003). This reduction most probably signifies a relative increase of posterior association cortex and is the first evidence of an important reorganization of the cerebral cortex toward a human-like pattern. The associated postcranial materials from both Hadar and Laetoli in Tanzania indicate an upright, striding gait, which, in turn, suggests existence in an adaptive mixed ecological niche of feeding and other behaviors different from that of any forest-dwelling ape. This adds to our conviction that if the hominid was operating in a different behavioral manner, it is more than likely that the brain was reorganized differently than in apes. These conclusions were voiced earlier by Holloway (1967, 1972a, 1975, 1983b, 1995, 1996) and Holloway and Post (1982). We can answer the question as to whether the increase of cranial capacity over an earlier ape-like volume of less than 400 ml preceded the reorganizational event that led to the relative increase in posterior association cortex: AL 162-28, Stw505, possibly AL 288-1, and most likely Taung and SK 1585, strongly suggest that reorganization did precede brain expansion. Admittedly, the

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Figure 140. Brain size by age and species. Stw 505 brain volume (greater than 550 ml) is larger than most chimpanzees, but it would be reasonable to expect that the Stw 505 body size was also greater. We can quibble about these absolute and relative brain sizes, but the major point seems clearly proved: the hominid brain underwent reorganization before it underwent any major expansion in size. As Figure 140 shows, early hominid brain volumes are mostly static throughout the evolutionary life span from the Hadar specimens through the Pliocene gracile South African specimens (e.g., Taung), although the latter probably shows a slight nonallometric increase in brain size over the earlier AL 444 condition. More specimens will be necessary to demonstrate this. Included in this apparent stasis of brain size is the one incomplete brain endocast available for A. garhi, reconstructed to 450 ml. The robust australopithecines, a side branch not leading or contributing to the Homo line, are clearly larger-brained than their A. africanus cousins, but this increase was likely an allometric one related to a larger body size. This stasis was perhaps some two million years in duration, during which it is likely, but as yet unproved, that our ancestral Homo lineage was beginning to branch off from either A. africanus

or A. garhi, most likely the latter, given the remaining dental and cranial evidence (Asfaw et al., 1999). The robust australopithecine represented at Swartkrans by SK 1585 (Holloway, 1972b) shows a clear left occipital asymmetry and a puckering in the posterior occipital lobe, suggesting a reduction of primary visual cortex. This can hardly be taken as proof, however. Perhaps the earliest Homo line had brains not only leading to a dramatic size increase but also showing the petalial patterns associated with true handedness and also cerebral hemispheric specialization. Yet the A. boisei forms, such as OH 5, Konso, or KNM-ER 406, do not appear to show such clear asymmetries. Nor do the earlier West Lake Turkana specimens unambiguously indicate either enlarged or reorganized brains. We tentatively agree with Falk et al. (2000) that the A. africanus prefrontal lobe appears less pointed than in earlier australopithecine specimens, but we also believe that caution is necessary because this feature is quite variable even for Pan troglodytes and P. paniscus. Their Broca’s cap regions do not appear human-like on the specimens currently available. This suggests that with increasing adaptations to mixed environments, and a gradual desiccation of forests, natural selection favored a brain

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organization capable of appreciating spatial relationships and object properties more advanced than those we know for Pan (see Holloway, 1996). At roughly 2 MYA there must have been important environmental changes that led, in part, to the evolutionary branching of hominids that were more advanced both brainwise and postcranially. These have been referred to as the habilines, based on the earliest finds, designated as Homo habilis from Olduvai Gorge, Tanzania, made by the Leakey family. These fossils show an enlarged cranial capacity ranging from roughly 590 ml (OH 24) to close to 700 ml (OH 7). The KNM-ER 1470 and KNM-ER 1590 specimens at roughly 1.8 MYA are clearly larger brained and larger bodied than those from Olduvai Gorge. The more recent taxonomic assignment of these specimens to Homo rudolfensis, and the later split of KNM-ER 3733 and KNM-ER 3883 from the KNM-WT 15000 specimen reflected by the division between Homo ergaster and Homo erectus, is not particularly convincing to us, though we accept the designations as convenient identities. The latter specimens range from 752 ml in KNM-ER 1470 to roughly 900 ml in the Nariokotome youth, KNMWT 15000. The picture is further complicated by other hominid specimens such as KNM-ER 1813 and KNMER 1805, as well as the diminutive OH 62. Added to this complex picture is the recent announcement of the Dmanisi Georgian finds as Homo georgicus (Gabounia et al., 2002), although it clearly establishes that there was a very early “out-of-Africa” migration that was a tremendously important event in the evolution of more modern Homo erectus groups in both Europe and Asia. The remains of the Olduvai specimens are either distorted (as in OH 24) or very incomplete (as in OH 7, 13, and 16). The reorganizational patterns are not apparent, although Tobias (1987) has claimed a left parietal petalial pattern for OH 7, an observation we find difficult to accept given the crushed condition of the original fragments. It is important to point out that none of these specimens, except for the extremely fragmented OH 16 and the highly distorted OH 24 specimens, possesses a frontal lobe. There is not enough material available to discuss cerebral asymmetries, reduction of area 17, PVC, or the Broca’s cap regions of the third inferior frontal convolution. The OH 12 endocast shows a clear posteriorly oriented lunate sulcus. However, with KNM-ER 1470, there is clearly a left occipital–right frontal petalial pattern, and Broca’s cap regions that are definitely more like those of Homo than Pan or early australopithecines from the

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A. africanus group. The Broca’s cap regions were noticed by Holloway in 1974, reported by Leakey in his two books (1978, 1992), and independently reported by Falk (1983). The Broca’s cap region of KNM-WT 15000, the Nariokotome youth, is not available in that specimen, or in OH 9, but subsequent Homo erectus specimens from Indonesia do show a Homo-like pattern of both enlargement and morphology. The Dmanisi fossils from Georgia, Eastern Europe, while not fully described, apparently have brain endocast values in the 650 to 750 ml range (Vekua et al., 2002). Unfortunately, the postcranial elements from Olduvai Gorge are too few and too fragmentary to provide useful estimates of body size. From the tiny foot from OH 8, and the smallish elements of OH 62, however, it would appear that these early habilines were anything but big bodied. This leads us to speculate that perhaps the increase in brain size was a nonallometric process, reflecting real selection pressures for a more advanced behavioral adaptation based on cerebral enlargement. As for KNM-ER 1470, we simply do not know its body size, but we regard it as unlikely that the increase in brain volume to between 750 and 800 ml was a purely allometric increase based on an increase in body size alone. We are certain, however, that Homo erectus (and here we include H. ergaster) had a body size nearly indistinguishable from modern Homo sapiens. There was a significant enlargement of brain volume that was not allometrically related to body size increase in much of Homo erectus, to archaic Homo (H. heidelbergensis) as represented by Steinheim, Swanscombe, Atapuerca, Ceprano, Petralona, Reilingen, and so on, through to the Neanderthals, where there indeed might have been an increase in skeletal robusticity with an attendant allometric increase in brain size (see for example Holloway, 1985). Homo erectus and subsequent fossil hominids clearly show cerebral asymmetries and Broca’s cap regions of modern human form. Nevertheless, we cannot be sure that there were not slight changes in the latter leading to modern human behavior. It is important to remember that we are dealing with tiny sample sizes when we talk about brain endocast features such as asymmetries in Broca’s caps, or left-right petalial patterns associated with both handedness and cerebral specializations between analytical and more gestalt-like cognitive processes. The record is intriguing, but not ironclad. We see absolutely nothing, however, in these later forms of Homo that would, based on neuroanatomical evidence alone, lead us to conclude that language behavior was not possible.

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Other fossil hominids, such as KNM-ER 1813 and 1805, are frankly puzzling, and perhaps can be viewed as advanced australopithecines or as examples of a miniadaptive radiation of early Homo hominids. While it is common to view KNM-ER 1813 as simply a female KNM-ER 1470 (Stringer 1986; Wolpoff, 1999), we feel that the degree of dimorphism of brain volume (510–752 ml) and brain endocast morphology does not support the suggestion that they are the same species. KNM-ER 1805 is a particularly difficult specimen to place. We would be more willing to entertain the speculative possibility that KNM-ER 1805 and KNM-ER 1813 are sexually dimorphic forms of a different early Homo (or advanced australopithecine) line, at least from the viewpoint of brain volume, although the ectocranial morphologies are quite different (Holloway, 1978, 1983b). If these conclusions, drawn from the paleoneurological and other cranial and postcranial evidence, are correct, most of the important reorganizational changes were complete by between 1.5 and 2.0 MYA. It may be that further changes both in cerebral asymmetries, Broca’s and Wernicke’s regions, and other cerebral, cerebellar (see Weaver 2001), and subcortical regions such as the limbic system took place, but aside from the cerebellum, we cannot detect these with our present methods. This leaves us with a considerable hiatus in Europe in large part because the Atapuerca and Dmanisi endocasts are not yet described (aside from estimates of brain volume). It also leaves us with the Neanderthals (as represented at least in Western Europe) showing enlarged cranial capacities and no evidence of cerebral primitiveness, except in the platycephalic shape of the crania. Most emphatically, we see no differences in the morphology of the prefrontal portion of the frontal lobe, a finding congruent with the morphometric analysis of Bookstein et al. (1999). While the Neanderthals might have been a separate species (in the sense of a morphospecies and not a biological species in the modern “Mayrian” sense), we do not see how either the behavioral or underlying neurological morphological evidence from brain endocasts contributes to such a view. We prefer to regard Neanderthals as separate from modern Homo sapiens at only the subspecific level (Holloway, 1985), but of course remain open to more convincing evidence on this issue. The 160,000 year-old Herto Homo sapiens idaltu crania (White et al., 2003) will eventually yield endocranial remains that are essentially the same as in modern Homo sapiens (e.g., size, asymmetries, lobar patterns, and perhaps meningeal vessels).

Behavioral Dynamics While much has been (and is) made of the nearquantum-like cultural advances beginning in the Upper Paleolithic with “true” Homo sapiens—such as blade tool traditions, carvings, parietal art, jewelry, sewing, and religious rites (e.g., see Klein, 1999; Klein and Edgar, 2002; and several papers in Crow, 2002)—we regard cultural dynamics as the most likely explanation for these advances, rather than neurological/behavioral changes in cognitive capacities based on a single or multiple mutations or the acquisition of neural modules (i.e., Ducheine et al., 2001). It is, though, theoretically possible that advances in our understanding of the genetic elements that relate to brain development might illuminate how the human brain evolved at this level (see Preuss et al., 2003). The findings of Paabo (2003), showing far greater genetic differences in brain genomic material for Homo than chimpanzee, clearly suggest that natural selection has operated on the neurogenetics of human brain evolution. If one thinks about the differences in cultural behavior from the time of, say, Edison to the present with the use of computers and our dependence on rapid exchanges of information, Satillites and the like, one should be a little skeptical about underlying mutations subserving cognitive abilities that conveniently sprang into being some 50,000 years ago. We believe that we have remained the same species, and were perhaps the same species 150,000 to 200,000 years before that. If one were to only think of the nonperishable remains (i.e., stone tools) of the Australian Aborigines, we would still be having difficulty understanding the complexity of their social structural systems. Would not our great-grandfathers, indeed, grandfathers, be amazed at the obvious differences in intellectual, material, and spiritual lifestyles that have “evolved” from their lifetimes to ours without any empirical demonstration of genetic mutations underlying such behaviors? The earliest phases of hominid existence are particularly open to speculative embroidery. But when all is said and done, it remains the stone tool industries or traditions that can inform us the most about hominid cognitive abilities. This does not mean that we disregard archaeological contexts such as the faunal remains, home bases, the evidence (or lack of it) for fire, importation over long distances of stones used in making tools, de-fleshing carcasses, or even cannibalism. Holloway (1967, 1969, 1981) suggested that stone tool making and language might have had similar cognitive underpinnings, particularly if the stone tools showed clear evidence of standardization of form from elements

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(e.g., cobbles) that had very different initial shapes. We appreciate that different stone materials can lead to a certain constraint in final form, but we still regard standardization as most likely culturally driven. We are, however, also intrigued by Weaver’s (2001) thesis that shifts in absolute and relative cerebellar size during hominid evolution might have had important correlations with both sensorimotor and cognitive processing. Since hominids were surely no less vocal and no less noisy than their ape cousins, we find it difficult to assert that there was a gestural stage in early hominids of the genus Homo (e.g., Hewes, 1973; Corballis, 2002). With Homo erectus, stone tools are clearly highly standardized in form. There is clear evidence of hunting and very likely scavenging and home bases. Brain sizes are within that for modern Homo sapiens, and the endocasts indicate modern Homo-like asymmetries in the hemispheres and even in the Broca’s cap regions. Of course, these associations cannot prove language, but the correlations are surely suggestive. We thus fall clearly into an early language camp for the genus Homo, however primitive it might have been. Still we do not believe that any species of Australopithecus possessed language abilities, although we can certainly accept that their communicative social skills and manipulation of the environment—in terms of collecting, scavenging, perhaps some hunting, and rudimentary tool making and use—were greater than those for extant chimpanzees, which themselves are beginning to appear more complex than previously thought. Language, of course, involves more than the brain, and much speculation has been presented suggesting that the descent of larynx has been an important if not absolutely essential ingredient in the development of hominid language. We are intrigued by recent reports that show laryngeal descent in chimpanzees (Nishimura et al., 2003) and even red deer (Fitch and Reby, 2001), for this clouds the picture as to how important laryngeal descent and cranial base flexion might have been in the evolution of hominid capacity for language. We rather feel that it was the neural elements that were most critical, with laryngeal position being important only in the phonation of modern human speech. Recently Heim et al. (2002) have suggested that the vocal tract of Neanderthals was morphologically similar to modern humans and that their larynx was situated at the same level as in modern humans. This conclusion is based on a newer reconstruction of the cranial base. They say: “. . . we do feel safe in saying that Neanderthals were not morphologically handicapped

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for speech” (p. 130), and they claim that Neanderthals could pronounce vowels “as differentiated” as those of ourselves. We concur that combined with any lack of primitive features in the Neanderthal brain, at least as evidenced by the endocasts, we see no reason why Neanderthals were not fully capable of human speech. We regard heterochronic changes, based on evolving regulatory-gene controlled endocrine-target tissue interactions, as the most probable explanation for changes in allometric and nonallometric evolution of the brain as suggested by Holloway (1967, 1975, 1979, 1995). In essence, we suggest at least three stages.

Stage 1 Early australopithecine phase, leading to early Homo, emphasizing social and behavioral adaptations, endocrinetargeted tissue and brain reorganization; beginning development of cerebral asymmetries, suggesting cognitive specializations in different hemispheres; and relative enlargement of posterior parietal association cortex, with possible changes in prefrontal cortex, but not necessarily including Broca’s cap regions. The early australopithecine phase includes the development of a more cooperative, dimorphic sex-role social grouping than in apes. These social changes were based on genetic changes involving hormones and target tissues that affected the developmental schedules of the brain and body. Earlier this was described as the “initial kick” in what was called “deviation-amplification” (i.e., the continuing action of positive feedback between such changes as in the “initial kick” and enlargement of brain and body size) (see Holloway, 1967, for a description). There was probably a concomitant reduction of sexual dimorphism in tooth and body size but an increase in epigamic features of secondary sexual characteristics, such as permanent enlarged breasts and different distributions of adipose tissue in females. There were probably also behavioral changes that led to a schedule of sexual receptivity different from that in apes, at least as characterized by Pan troglodytes. These changes probably meant a set of closer and more cooperative complemental relationships between males, females, and offspring. This set of correlated behavioral, physiological, and anatomical adaptations led to more efficient mating strategies that were essential for the prolonged periods of postnatal dependence and learning, and the delay of sexual maturation—a set of potentially risky adaptations in an evolutionary sense. Changes in the interactions between hormonal and target tissue milieus might have led to a reduction in aggressive

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behavior, or a heightened threshold to within-group aggression, permitting groups to live more densely with more cooperative behavior as better protection against both predators and other hominid groups. Concomitantly, hormonal-target tissue changes affected growth rates (longer durations of growth and prolonged dependency), possibly with some allometric increase in brain growth that would have been reflected in slightly higher EQs than in apes. Their bipedalism most probably allowed for greater ranges of econiche diversity and exploration, and their growing sophistication about objects and spatial relationships was probably instrumental in selection for a relative reduction in PVC and a relative expansion of posterior parietal lobe. Extension of foresight and memory would obviously have been advantageous, and appear to us to be nascent in these hominids given their somewhat broader prefrontal lobes and expanded temporal lobes. Later australopithecines probably were using tools but were not showing clear standardization of form either in their choice of tools or their manufacture, the earliest evidence for stone tools going back to approximately 2.6 MYA. If social communicatory skills were greater at this stage than what we witness in extant chimpanzees, this would most likely have been associated with social affect and control than with hunting behavior.

behaviorally. These in turn provided the basis for increasing postnatal dependency and learning, increasing age toward parturition, and the increased duration of childhood to sexual maturity. Social learning of tool making, hunting, collecting, scavenging, and reproductive strategies were all in a positive feedback system between cultural complexity and brain enlargement, but only to the extent that basic obstetrical constraints were not broached. As Holloway noted in this regard (1975: 40): Language behavior became more strongly developed and cognitive behavior of a more nearly human type developed, where language and tool-making arose from the same psychological structuring. There were true stone tool “cultures” at this stage, and language had prime importance in maintaining social cohesion and control and in “programming” offspring. Dependence on hunting increased and there was more success in stalking and hunting larger game. There was a selection for increased body size, bipedal agility and predictive abilities for more successful hunting (meaning the full food quest in which women and children are important contributors). The social behavioral changes outlined in stages 1 and 2 permitted longer male-male associations for persistent hunting and for protection of a more secure home base for females and young, who were providing smaller game and vegetables. The “initial kick” or “human revolution” is fully set and leads to stage 3.

Stage 2 Later early Homo–early Homo erectus phase, emphasizing consolidation of stage 1 and the development of language capacities; clear-cut and modern-human-like cerebral asymmetries, including Broca’s cap regions of the prefrontal cortex, and both allometric and nonallometric increases of brain volume, with attending increases in EQ. This stage included elaboration and augmentation of the changes in social behavior mentioned in stage 1. More important, it involved a growing dependence on social cohesion, cooperation, and sex-role complementation in all economic tasks, involving beginning language based on arbitrary symbols, however primitive, and the manufacturing of stone tools to standardized patterns with clear cognitive associations between different tools and tasks. Bipedal locomotion was fully human. The brain expanded in size both absolutely and relatively, reflecting more hormonal-target-tissue interactions in the modern human direction. These changes led to further reductions in size dimorphism between the sexes with a possible increase in secondary sexual dimorphism, physiologically, anatomically, and

Stage 3 Growing elaboration of cultural skills, based certainly on language, using arbitrary symbol systems, and developing through an on-going positive feedback relationship between behavioral complexity and brain enlargement; also continuing refinements in hemispheric asymmetries, and hemispheric specialization for visuospatial, verbal, and sociality skills developed in stage 2. Stage 3 is us and, we believe, characteristic of Neanderthals. It seems to us unlikely that major changes in postnatal dependency time, gestation, parturition, or reproductive age occurred during this stage, having been for the most part completed in archaic Homo sapiens (H. heidelbergensis) and pre-Neanderthalien times, as seen at least in Western European Neanderthals of the “classic” sort. We also believe that it was a stage during which increased learning would have been extremely important and under fairly stringent social control, as cultural complexities were occurring in more complex and stimulating material and social environments. The major neurological changes were probably minor

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increases of size and refinement of the already reorganized brain, in sensorimotor, associative, and extrapyramidal (striatum) modulation, as well as cerebellar involvement in manual dexterity, language, and artistic development such as song, dance, and tool making. A fourth stage might be suggested, when there occurred a gradual and small decrease in our absolute brain size from the Upper Paleolithic to today’s time period, as suggested by Henneberg (1998). This would most surely be explained as an allometric decrease based on a loss of bony/muscular robusticity, without any significant behavioral associations. We expressly disagree with our colleagues who believe that somewhere in this third stage, a single mutational event made language and art possible, and that one had to witness what many appear to regard as an Upper Paleolithic “revolution” before the brain was adequate to the tasks of full symbolic language and art. We also regard these stages as fairly continuous, but we do not rule out the possibility of mosaics within the mosaic, so to speak. These temporal changes were probably not gradual but “punctuated” within space, frames of thousands of years. In the human mind’s natural desire for closure, it is particularly difficult to accept that our fossil record is so extraordinarily limited. It is a simple task to assume a generation span of, say, 20 years and a constant essential population (Ne ) size of 500 reproducing souls during any generational span. Over the course of the past 1,000,000 years (to select an easily calculable figure), how many individuals would have lived during that time? 50,000 generations times 500 souls per generation comes out to be 25,000,000 individual hominids. What, however, is our present-day sample of endocranial casts that reveal something about how the brain evolved? Just to simplify our calculations, assume we have a sample of 100 endocasts. The percentage of possible hominid remains that we have sampled is 0.000004, or .0.004%! An order of magnitude difference in any our assumptions would make little difference. On the one hand, it is remarkable how much scientists can make from so little, but we prefer to be humble in our assessment of how closely we can describe hominid evolution, and in particular, our brains. Even with a time machine, how long would it take one or some of us to observe and measure the brains and behavior of some 25 million hominids? We have attempted to show in these pages that the evolution of the human brain has always been an important integral aspect of hominid evolution and not just

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something that took place following changes in other morphological components of the hominids, such as bipedal locomotion, the refinement of precision grip, carrying objects, or language. None of these components can operate (nor did they) in neurological vacuums. A change in locomotory pattern signals not simply a change in musculoskeletal relationships but also in innervations, and motor control, and these newer constellations of musculoskeletal patterns themselves operate within different ecological and thus behavioral contexts. Endocasts are not alone, at this juncture of their study, a sufficient basis for delineating the exact neurological changes that accompanied behavioral adaptations such as throwing, bipedal locomotion, precision gripping, stone tool making, artistic appreciation and rendition, song, dance, humming, or whatever other behavioral attributes we consider as part and parcel of humanness. Our study of endocasts does convince us, however, that human behavior is a long-standing evolutionary development, possibly three million years old, and not a late invention dependent on a few salutary mutations. Regulatory genes can probably explain much of the progression. The human brain is both the product and cause of our evolutionary pathway, and certainly is the instrument and product of our sociality, wonderful and/or frightening as that may be.

Endocasts Yet to Be Studied Listing all of the endocasts, actual and potential, is not to be taken to mean that those described in this volume have been sufficiently or completely studied. Indeed, we have voiced our honest hope that other researchers might regard these objects as worthy of further study. The fact remains that there some glaring hiatuses in our attempt to be thorough, and we mention them below in the hope of encouraging those in charge of the fossils, or those desiring to work on them, to endocast the fossils and permit access for further study. Among the South African australopithecines, we underline the desirability of further study on Sts 58, the dorsal calva portion associated with Sts 19, described herein. We have not seen any mention of the newer Dremolin Cave finds, and possible endocasts or portions of endocasts that could be made. The debates between one of us (RLH) and Dean Falk should encourage independent study of both the volumes and morphology of the endocasts of these hominids. In particular, independent study of SK 1585 should be initiated given the wide disagreement between Falk

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et al. (2000) and Holloway (1972b), and Holloway et al. (2000) regarding its volume. While all of the considerations above apply to both Kenyan and Ethiopian endocasts, we believe we have described most of them, as has Tobias (1991). On the other hand, hominids such as KNM-ER 406, KNMER 407, and KNM-ER 732 should be re-studied (and re-cast), since RLH’s original endocasts were left in Nairobi and have long since deteriorated. The descriptions in this volume are based on plastic replicas of often poor quality. KNM-ER 406 is filled with extremely hard matrix and requires much more study through modern scanning techniques, as it is very unlikely that the matrix can ever be removed without seriously damaging the original cranium. An accurate volume estimate would be most welcome. Newer finds, such as Kenyanthropus platyops, and other fragments from Lomekwi, should yield, through modern scanning techniques, a good opportunity to find an accurate volume, particularly in lieu of White’s (2003) assessment of possible distortion to the holotype, KNM-WT 40000. Naturally recent discoveries such as Orrorin, Sahelanthropus and Ardipithecus will yield both volumetric and morphological features that will assist in understanding the earliest phases of hominid brain evolution. To our current understanding, the fragments of these crania are too incomplete to provide such information, but the future always holds promise! The earliest Homo specimens from Tanzania (OH 7, 12, 13, 16, and 24) are particularly in need of further study, building on Tobias’s scholarly treatise (1991). The originals that RLH made in the early 1970s have surely disintegrated, and the plastic replicas in his collection are of poor quality. Similarly KNMER 1470 and KNM-ER 1590 should be recast and independently studied, particularly with regard to petalial asymmetry patterns and the possibility of cerebral hemispheric specialization, as well as the Broca’s cap region. The former is of key importance regarding questions about brain reorganization in the Homo line. Indeed, the same applies to KNM-ER 1805 and KNMER 1813. These two endocast portions are particularly difficult to assign with any taxonomic closure given their unusual morphology, although we stand confident regarding our volume determinations, whether they are truly early Homo or advanced australopithecines. The Dmanisi specimens of 1.8 MYA are extremely important, both with respect to accurate volumes and possible morphological features. We look forward to reading studies on their paleoneurological information.

From our examination of the various photographs of these specimens, we are certain that they can be safely endocast, and would be willing to do so. As far as we are aware, the Atapuerca crania from Spain (4 and 5) have yielded accurate volumes, and their morphological characteristics are under study by Arsuaga’s team. Our attempts to gain information about these possible endocasts have not been answered. Given the prospects that their internal tables of bone are perfectly preserved, the paleoneurologists’ appetites should indeed be whetted. These represent a major hiatus in our understanding of possible Neanderthal ancestry and the European hominids in general. The Steinheim hominid (Germany) is yet another hiatus in the domain of paleoneurological study. Although an accurate volume determination will probably result from newer scanning devices and restorative techniques, it is preferable to have an actual endocast of silicon rubber to palpate. Indeed, even a distorted version is preferred to nothing, which is our current situation. Similar comments can be made for the well-preserved Petralona (Greece) and Ceprano (Italy) specimens. All of these are important for a better understanding of European hominid evolution and their variability. Newer Indonesian finds such as Sm 4 (Baba et al., 2003) are important additions to our increasing sample of Indonesian specimens of Homo erectus, which to date show little in the way of either volumetric or morphological variation, an evolutionary potentially interesting facet of the evolution of the genus Homo, and OOA (out of Africa) and MRE (multiregional evolution) controversies. We are very fortunate to have had the opportunity to describe Sm 3, the Poloyo hominid of NYC boutique fame. Several Chinese hominid crania (aside from the older Zhoukoudian discoveries originally named Sinanthropus pekinensis), such as Lantian, Maba, Yunxian 2, Nanjing, Hexian, Shandong, Dali, and Jinniushan, have not been endocast to our knowledge, and a few may be particularly difficult to endocast given their fragmentary and deformed condition. Hopefully these will be added to our paleoneurological sample in the future. Finally we note that there are several important gaps in our studies of Neanderthal endocasts. In particular, the Italian Saccopastore hominid cranial portions could be endocast, adding very important volumetric and morphological details to the abundant controversies over these hominids. Furthermore the Middle Eastern Neanderthals of the Mount Carmel and Shanidar caves have not been studied by us given problems of access

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and their fragmentary nature. They are likely to be an important pivotal point in our understanding of Neanderthal evolutionary dynamics, whether or not one agrees with different species designations for these and modern anatomical Homo sapiens.

References Asfaw B, White T, Lovejoy O, Latimer B, Simpson S, Suwa G. 1999. Australopithecus garhi: A new species of early hominid from Ethiopia. Science 284:629–635. Baba H, Aziz F, Kaifu Y, Suwa G, Kono RT, Jacob T. 2003. Homo erectus calvarium from the Pleistocene of Java. Science. 299:1384–1388. Bookstein FL, Schafer K, Prossinger H, et al. 1999. Comparing frontal cranial profiles in archaic and modern Homo by morphometric analysis. Anat Rec (New Anat) 6:217–224. Corballis M. 2002. Laterality and human speciation. In: Crow TJ, ed, The Speciation of Modern Homo sapiens. Oxford: Oxford University Press, pp 137–152. Crow TJ, editor. 2002. The Speciation of Modern Homo sapiens. Oxford: Oxford University Press. Duchaine B, Cosmides L, Tooby J. 2001. Evolutionary psychology and the brain. Curr Opin Neurobiol 11:225–230. Falk D. 1983. A reconsideration of the endocast of Proconsul africanus: implications for primate brain evolution. In: Ciochon RL, Corruccini RS, eds, New Interpretations of Ape and Human Ancestry. New York: Plenum, pp 239– 248. Falk D. 1983. Cerebral cortices of East African early hominids. Science 221:1072–1074. Falk D, Redmond JC, Guyer J, Conroy GC, Recheis W, Weber GW, Seidler H. 2000. Early hominid evolution: A new look at old endocasts. J Hum Evol 38:695–717. Fitch WT, Reby D. 2001. The descended larynx is not uniquely human. Proc R Soc Lond B 268:1669–1675. Gabounia L, de Lumley M-A, Vekua A, Lordkipanidze D, de Lumley H. 2002. D´ecouverte d’un nouvel hominid´e a´ Dmanissi (Transcaucasie, G´eorgie). C R Palevol 1:243– 253. Heim J-L, Bo¨e L-J, Abry C. 2002. La parole a` la port´ee du conduit vocal de l’homme de Neandertal. Nouvelles recherches, nouvelles perspectives. Compte Rend. Palevol 1:129–134. Henneberg M. 1998. Evolution of the human brain: is bigger better? Clin Exp Pharmacol Physiol 25:745–749. Hewes GW. 1973. Primate communication and the gestural origin of language. Curr Anthropol. 14:5–24.

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Holloway RL. 1967. The evolution of the human brain: some notes toward a synthesis between neural structure and the evolution of complex behavior. Gen Sys 12:3–19. Holloway RL. 1969. Some questions on parameters of neural evolution in primates. In: Petras J, Noback C, eds, Comparative and Evolutionary Aspects of the Vertebrate Central Nervous System. Ann NY Acad Sci 167:332–340. Holloway RL. 1972a. Australopithecine endocasts, brain evolution in the Hominoidea and a model of hominid evolution. In: Tuttle R, ed, The functional and evolutionary biology of primates. Chicago: Aldine/Atherton Press, pp 185– 204. Holloway RL. 1972b. New australopithecine endocast, SK1585, from Swartkrans, S. Africa. Am J Phys Anthropo 37:173–186. Holloway RL. 1975. The Role of Human Social Behavior in the Evolution of the Brain. The 43rd James Arthur Lecture on the Evolution of the Human Brain. New York: The American Museum of Natural History. Holloway RL. 1978. Problems of brain endocast interpretation and African hominid evolution. In: Jolly C, ed, Early Hominids of Africa. London: Duckworth, pp 379–401. Holloway RL. 1979. Brain size, allometry, and reorganization: toward a synthesis. In: Hahn ME, Jensen C, Dudek BC, eds, Development and Evolution of Brain Size: Behavioral Implications. New York: Academic Press, pp 59–88. Holloway RL. 1981. Culture, symbols, and human brain evolution: A synthesis. Dialect Anthropol. 5:287–303. Holloway RL. 1983a. Cerebral brain endocast pattern of Australopithecus afarensis hominid. Nature 303:420–422. Holloway RL. 1983b. Human brain evolution: A search for units, models, and synthesis. Can J Anthropol 3:215– 232. Holloway RL. 1985. The poor brain of Homo sapiens neanderthalensis: See what you please. In: Delson E, ed, Ancestors: The Hard Evidence. New York: AR Liss, pp 319–324. Holloway RL. 1995. Toward a synthetic theory of human brain evolution. In: Changeux J-P, Chavaillon J, eds, Origins of the Human Brain. Oxford: Clarendon Press, pp 42–54. Holloway RL. 1996. Evolution of the human brain. In: Lock A, Peters C, eds, Handbook of Human Symbolic Evolution. New York: Oxford University Press, pp 74–116. Holloway RL, Post DG. 1982. The relativity of relative brain measures and hominid mosaic evolution. In: Armstrong E, Falk D, eds, Primate Brain Evolution: Methods and Concepts. New York: Plenum, pp 57–76. Holloway RL, Yuan MS, M´arquez S, Broadfield DC, Mowbray K. 2000. Extreme measures of SK 1585 brain endocast: The endocranial capacities of robust australopithecines revisited. Am J Phys Anthropol Supp 30:181–182.

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Holloway RL, Broadfield DC, Yuan MS (2003) Morphology and histology of the chimpanzee primary visual striate cortex indicate that brain reorganization predated brain expansion in early hominid evolution. Anat Rec 273A:594– 602. Klein RG. 1999. The Human Career: Human Biological and Cultural Origins, 2nd ed. Chicago: University of Chicago Press. Klein RG, Edgar B. 2002. The Dawn of Human Culture. New York: Wiley. Leakey RE, Lewin R. 1978. People of the Lake: Mankind and Its Beginnings. Garden City, NY: Anchor Press. Leakey RE. Lewin R. 1992. Origins Reconsidered: In Search of What Makes Us Human. London: Little, Brown. Nishimura T, Mikami A, Suzuki J, Matsuzawa T. 2003. Descent of the larynx in chimpanzee infants. Proc Natl Acad Sci USA 100:6930–6933. P¨aa¨ bo S. 2003. The mosaic that is our genome. Nature 421:409–412. Preuss TM, C´aceres M, Laucher J, et al. 2003. Using genomics to identify human brain specializations. Am J Phys Anthropol Suppl 36:171. Radinsky LB. 1974. The fossil evidence of anthropoid brain evolution. Am J Phys Anthropol 41:15–28.

Radinsky LB. 1975. Primate brain evolution. Am Sci 63:656– 663. Stringer CB. 1986. The credibility of Homo habilis. In: Wood B, Martin L, Andrews P, eds, Major Topics in Primate and Human Evolution. Cambridge: Cambridge University Press, pp 266–294. Tobias PV. 1987. The brain of Homo habilis: A new level of organization in cerebral evolution. J Hum Evol 16:741–762. Tobias PV. 1991. Olduvai Gorge, Vols 4A, 4B: The Skulls, Endocasts, and Teeth of Homo habilis. Cambridge: Cambridge University Press. Vekua A, Lordkipanidze D, Rightmire GP, et al. 2002. A new skull of early Homo from Dmanisi, Georgia. Science 297:85–89. Weaver AGH. 2001. The cerebellum and cognitive evolution in Pliocene and Pleistocene hominids. PhD Thesis. University of New Mexico. White TD. 2003. Early hominids—Diversity or distortion? Science 299:1994–1997. White TD, Asfaw B, DeGusta D, et al. 2003. Pleistocene Homo sapiens from Middle Awash, Ethiopia. Nature 423:742–747. Wolpoff M. 1999. Paleoanthropology, 2nd ed. New York: McGraw-Hill.

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Notes for Appendix 1 The endocranial volumes for this table are listed by taxonomic group as currently expressed in the literature, and arranged alphabetically within broad geographic regions. Our use of these taxa in this Table does not mean that we concur with all of these designations. Where the “source” indicates an “RLH” that means the endocranial capacities were either determined by RLH or published RLH as in Holloway, RL. 2000. Brain. In: E. Delson, I. Tattersall, J. Van Couvering, and AS Brooks (Eds). Encyclopedia of Human Evolution and Prehistory. 2nd Edition. NY: Garland Publ., Inc. pps. 141–149. If the “Source” is “OTHER”, the volumes reported were taken from the recent literature as found in our Bibliography, and mostly from

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Ruff, CB, Trinkaus, E., and Holiday, TW. 1997. Body mass and encephalization in Pleistocene Homo. Nature 387:173–176 (Supplementary Data). The SM 1 and SM 4 volumes are from Baba et al. 2003. Homo erectus Calvarium from the Pleistocene of Java. Science 299: 1384–1388. We have decided to provide a chronological age for each endocranial volume to permit regressing endocranial volume against time. The range of MYA’s for many of the hominids are too wide to accept anything but a middle value, and we hope that these dates will become more accurate as new dating techniques become available. Missing, in particular, is any endocranial estimate for the Maba (China) cranium. We could not find a citation anywhere in the literature that we have seen.

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Source

Volume

Taxon

MYA

AL 162-28 AL 288-1 AL 333-105 AL 333-45 AL 444-2

RLH RLH RLH RLH RLH

400 387 400 492 550

A. afarensis A. afarensis A. afarensis A. afarensis A. afarensis

3.18 3 3.18 3.18 3

KNM-WT 17000 KNM-WT 17400 KNM-ER 23000 Omo L338y-6

RLH RLH RLH RLH

410 400 490 427

A. ethiopicus A. ethiopicus A. ethiopicus A. ethiopicus

2.5 1.77 1.7 2.39

KNM-ER 406 KNM-ER 407 KNM-ER 732 KNM-WT 13750 Konso (KGA-10-525) OH 5

RLH RLH RLH RLH RLH RLH

500 510 500 475 545 520

A. boisei A. boisei A. boisei A. boisei A. boisei A. boisei

1.5 1.85 1.7 1.7 1.4 1.8

SK 54 SK 859 SK 1585

RLH RLH RLH

500 450 530

A. robustus A. robustus A. robustus

1.5 1.5 1.5

MLD 1 MLD 37/38 Sts 5 Sts 19/58 Sts 60 Sts 71 Stw 505 Taung Type 2

RLH RLH RLH RLH RLH RLH RLH RLH RLH

510 435 485 436 400 428 560 440 457

A. africanus A. africanus A. africanus A. africanus A. africanus A. africanus A. africanus A. africanus A. africanus

3.1 3.1 2.5 2.5 2.5 2.5 2.6 2.6 2.5

Bouri (Bou-VP-12/130)

RLH

450

A. garhi

2.5

KNM-ER 1805 KNM-ER 1813 OH 7 OH 13 OH 16 OH 24

RLH RLH RLH RLH RLH RLH

582 509 687 650 638 590

H. habilis H. habilis H. habilis H. habilis H. habilis H. habilis

1.85 1.88 1.8 1.5 1.7 1.8

KNM-ER 3732 KNM-ER 3733 KNM-ER 3883

RLH RLH RLH

750 848 804

H. ergaster H. ergaster H. ergaster

1.88 1.78 1.57

KNM-ER 1470 KNM-ER 1590

RLH RLH

752 825

H. rudolfensis H. rudolfensis

1.88 1.85

Dmanisi D2280 Dmanisi D2282

Other Other

650 780

H. georgicus H. georgicus

1.7 1.7

Daka, Ethiopia Hexian Jinniushan

Other Other Other

995 1025 1390

H. erectus H. erectus H. erectus

1 0.412 0.28 (Cont.)

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Source

Volume

Taxon

MYA

KNM-WT 15000 Lantian (Gongwang 1) Narmada Ngawi OH 9 OH 12 Sale Sambungmacan 1 Sambungmacan 3 Sambungmacan 4 Sangiran 2 Sangiran 3 Sangiran 4 Sangiran 10 Sangiran 12 Sangiran 17 Trinil 2 Yunxian (1 and 2) Zhoukodian III, E (Z 2) Zhoukoudian (Z11) Zhoukoudian I, L (Z 10) Zhoukoudian III, L (Z 12)

Other Other Other Other RLH RLH RLH Other RLH Other RLH RLH RLH RLH RLH RLH RLH Other RLH RLH RLH RLH

900 780 1260 870 1067 727 880 1035 917 1006 813 950 908 855 1059 1004 940 1200 915 1015 1225 1030

H. erectus H. erectus H. erectus H. erectus H. erectus H. erectus H. erectus H. erectus H. erectus H. erectus H. erectus H. erectus H. erectus H. erectus H. erectus H. erectus H. erectus H. erectus H. erectus H. erectus H. erectus H. erectus

1.5 0.7 0.236 na 1.2 0.6 0.24 0.8 0.4 0.8 0.98 1 1.1 1.2 0.9 1 0.9 0.4 0.4 0.4 0.4 0.4

Atapuerca 4 Atapuerca 5 Atapuerca 6

Other Other Other

1390 1125 1140

H. antecessor H. antecessor H. antecessor

0.35 0.35 0.35

Dali 1 Ngandong 1 (Solo I) Ngandong 6 (Solo V) Ngandong 7 (Solo VI) Ngandong (Solo IX) Ngandong 13 (Solo X) Ngandong 14 (Solo XI)

Other RLH RLH RLH RLH RLH RLH

1120 1172 1251 1013 1135 1231 1090

H. soloensis H. soloensis H. soloensis H. soloensis H. soloensis H. soloensis H. soloensis

0.209 0.031 0.031 0.031 0.031 0.031 0.031

Arago Biache Bodo Ceprano Ehringsdorf Kabwe Lazaret Petralona Reilingen Saldanha Steinheim Swanscombe

RLH Other RLH Other Other RLH RLH Other RLH Other Other RLH

1166 1200 1250 1165 1450 1325 1250 1230 1430 1225 1200 1325

H. heidelbergensis H. heidelbergensis H. heidelbergensis H. heidelbergensis H. heidelbergensis H. heidelbergensis H. heidelbergensis H. heidelbergensis H. heidelbergensis H. heidelbergensis H. heidelbergensis H. heidelbergensis

0.4 na 0.6 0.8 0.23 0.18 0.13 0.21 0.2 0.5 0.225 0.25

Amud Engis 2 Ganovce

Other Other RLH

1740 1362 1320

H. sapiens neanderthalen H. sapiens neanderthalen H. sapiens neanderthalen

0.041 0.06 0.09 (Cont.)

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Source

Volume

Taxon

MYA

Gibralter (Devil’s) Gibralter (Forbe’s) Jebel Irhoud 1 Jebel Irhoud 2 Krapina B Krapina 3 (Cranium C) Krapina 6 (Cranium E) La Chapelle La Ferrassie La Quina 5 La Quina 18 Le Moustier Monte Circeo (Guat1) Neanderthal Saccopastore 1 Saccopastore 2 Shanidar 1 Shanidar 5 Skhul 1 Skhul 4 Skhul 5 Skhul 9 Spy I Spy II Tabun 1 Teshik-Tash

Other Other RLH RLH Other RLH RLH Other Other Other Other Other RLH Other Other Other Other Other Other Other Other Other RLH RLH Other Other

1400 1200 1305 1400 1450 1255 1205 1625 1640 1172 1200 1565 1360 1525 1245 1300 1600 1550 1450 1554 1520 1590 1305 1553 1271 1525

H. sapiens neanderthalen H. sapiens neanderthalen H. sapiens neanderthalen H. sapiens neanderthalen H. sapiens neanderthalen H. sapiens neanderthalen H. sapiens neanderthalen H. sapiens neanderthalen H. sapiens neanderthalen H. sapiens neanderthalen H. sapiens neanderthalen H. sapiens neanderthalen H. sapiens neanderthalen H. sapiens neanderthalen H. sapiens neanderthalen H. sapiens neanderthalen H. sapiens neanderthalen H. sapiens neanderthalen H. sapiens neanderthalen H. sapiens neanderthalen H. sapiens neanderthalen H. sapiens neanderthalen H. sapiens neanderthalen H. sapiens neanderthalen H. sapiens neanderthalen H. sapiens neanderthalen

0.05 0.05 0.1 0.1 0.13 0.13 0.13 0.05 0.07 0.065 0.06 0.041 0.052 0.04 0.125 0.125 0.06 0.06 0.1 0.1 0.1 0.1 0.068 0.068 0.11 0.07

Herto 1/16

Other

1450

H. sapiens idaltu

0.16

Brno I Brno II Brno III Border Cave Bruniquel 2 Cap Blanc 1 Chancelade Combe Capelle Cro-Magnon 1 Cro-Magnon 3 Dolni Vestonice 3 Dolni Vestonice 14 Dolni Vestonice 18 Dolni Vestonice 20 Dolni Vestonice 21 Grotte des Infants 4 Grotte des Infants 5 Grotte des Infants 6 Kostenki 2 Kostenki 14 Laetoli 18

Other Other Other Other Other Other Other Other Other Other Other Other Other Other Other Other Other Other Other Other Other

1600 1500 1304 1510 1555 1434 1530 1570 1730 1590 1285 1538 1481 1378 1547 1775 1375 1580 1605 1222 1367

H. sapiens sapiens H. sapiens sapiens H. sapiens sapiens H. sapiens sapiens H. sapiens sapiens H. sapiens sapiens H. sapiens sapiens H. sapiens sapiens H. sapiens sapiens H. sapiens sapiens H. sapiens sapiens H. sapiens sapiens H. sapiens sapiens H. sapiens sapiens H. sapiens sapiens H. sapiens sapiens H. sapiens sapiens H. sapiens sapiens H. sapiens sapiens H. sapiens sapiens H. sapiens sapiens

0.026 0.026 0.026 0.07 na na na 0.028 0.03 0.03 0.0275 0.0275 0.0275 0.0275 0.0275 na na na 0.02 na 0.12 (Cont.)

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Source

Volume

Taxon

MYA

Liujiang Minatogawa 1 Minatogawa 2 Minatogawa 4 Mladec 1 Mladec 2 Mladec 5 Nazlet Khater 2 Obercassel 1 Obercassel 2 Omo 2 (Kibbish) Pataud 1 Pavlov1 Predmosti 3 Predmosti 4 Predmosti 9 Predmosti 10 Qafzeh 6 Qafzeh 9 Qafzeh 11 San Teodoro 1 San Teodoro 2 San Teodoro 3 San Teodoro 5 Singa 1 St. Germain-la-Rivie Sungir 1 Sungir 2 Sungir 3 Sungir 5 Veyrier 1 Yinkou Zhoukoudian (Upper Cave) 1 Zhoukoudian (Upper Cave) 2 Zhoukoudian (Upper Cave) 3

Other Other Other Other Other Other Other Other Other Other Other Other Other Other Other Other Other Other Other Other Other Other Other Other Other Other Other Other Other Other Other Other Other Other Other

1480 1390 1170 1090 1540 1390 1650 1420 1500 1370 1435 1380 1472 1580 1250 1555 1452 1568 1531 1280 1565 1569 1560 1484 1550 1354 1464 1267 1361 1453 1430 1390 1500 1380 1290

H. sapiens sapiens H. sapiens sapiens H. sapiens sapiens H. sapiens sapiens H. sapiens sapiens H. sapiens sapiens H. sapiens sapiens H. sapiens sapiens H. sapiens sapiens H. sapiens sapiens H. sapiens sapiens H. sapiens sapiens H. sapiens sapiens H. sapiens sapiens H. sapiens sapiens H. sapiens sapiens H. sapiens sapiens H. sapiens sapiens H. sapiens sapiens H. sapiens sapiens H. sapiens sapiens H. sapiens sapiens H. sapiens sapiens H. sapiens sapiens H. sapiens sapiens H. sapiens sapiens H. sapiens sapiens H. sapiens sapiens H. sapiens sapiens H. sapiens sapiens H. sapiens sapiens H. sapiens sapiens H. sapiens sapiens H. sapiens sapiens H. sapiens sapiens

0.04 0.018 na na 0.03 na na 0.037 na na 0.12 na 0.026 0.026 0.026 0.026 0.026 0.09 na na na na na na 0.133 na 0.024 na na na na 0.13 0.015 na na

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APPENDIX 1 Part II: Average endocranial volumes and EQs TAXA A. afarensis A. africanus A. ethiopicus A. garhi H. erectus H. ergaster H. habilis H. heidelbergensis H. rudolfensis H. neanderthalensis H. sapiens H. soloensis A. robustus A. boisei P. troglodytes G. gorilla

Mean Volume (ml)

Mean MYA

BODYMASS

EQMARTIN

EQHOMO

445.80 462.33 431.75 450.00 941.44 800.67 610.00 1,265.75 788.50 1,487.50 1,330.00 1,155.86 493.33 515.00 405.00 500.00

3.11 2.66 2.09 2.50 0.81 1.74 1.76 0.27 1.87 0.08 0.01 0.06 1.50 1.65 0.01 0.01

37.00 35.50 37.60

4.87 5.21 4.66

42.79 45.58 41.01

57.80 57.50 34.30 68.70 45.60 64.90 63.50

7.32 6.25 7.06 8.64 7.35 10.60 9.63

67.64 57.72 61.50 81.30 66.08 99.14 89.90

36.10 41.30 46.00 105.00

5.49 5.17 3.75 2.47

48.11 46.02 33.75 24.39

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Provided herein are the initial basic statistics for all the hominid endocranial samples we described in this book. These statistics can be arranged differently, but we chose these various combinations because, by relying on consensual taxonomic placements, we were able to increase sample sizes within taxa. In addition to mean and standard deviation, we include minimum and maximum values, the coefficient of variation (CV), skewness, and kurtosis. If we assume that all hominid populations’ endocranial capacities were basically of a normal Gaussian nature, the strong deviations from such normality might signal clues regarding sampling and taxonomic placements. For example, populations with very large or very small CVs (i.e., departing strongly either way from about 10%) suggest caution is advisable. The CV for A. afarensis of 16.1% suggests a fairly dimorphic sample, or a combination of taxa. We believe the former to be the case despite the recent findings of Reno et al. (2003) regarding modern Homo-like sexual dimorphism of the femoral head in A. afarensis. On the other hand, the CVs for “all Homo erectus” are 16.2%, and 14.9% for early Homo, because these samples contain multiple taxa rather than strong sexual dimorphism in endocranial capacity. However, we are not claiming that CVs trump morphology, only that they might have a use in sensitizing us to question the basis for the high or low values. More sampling will of course resolve these questions. Similarly the low CVs for A. robustus/A. boisei probably signal a combination of low sample size and bias in

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TA X A

both discovery and methodological issues when reconstructing incomplete endocasts. Similarly the relatively low CVs for the Ngandong (Solo) and H. heidelbergensis groups suggest either sampling or reconstruction bias, whereas the A. africanus and H. habilis groups have CVs that are more in line with expectations for early hominid sexual dimorphism and population variation. We believe the same applies to H. erectus without H. ergaster, H. rudolfensis, and H. georgicus. Mostly from our findings, but including those of several other workers, on the accumulation of endocranial capacities, we propose an average endocranial capacity for H. sapiens neanderthalensis that is lower than that for modern Homo sapiens of the Upper Pleistocene. The addition of two smallish Krapina (3 and 6) specimens, less than 1275 ml, both probably females, could change our bias regarding the old paleanthropological “chestnut” that Neanderthal had brains larger than our own. As the modern Homo sample is unquestionably mostly male, this supposition requires more analysis than we can provide here. Similarly the skewness and kurtosis figures are only approximate due to imperfect sampling or clustering of taxa. In general, values greater or lesser than ±1.0 signal significant departures. We do not suggest any use of these statistics to determine either the correctness or wrongness of taxa. In general, these figures for skewness and kurtosis appear to be suggesting over-all Gaussian normality within taxa.

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Statistical Analysis of Endocranial Volumes by Taxa Taxa A. afarensis A. aethiopicus A. robustus & A.boisei A. boisei A. garhi A. africanus H. habilis (includes 1813, 1805) H. erectus (no ergaster, rudolfensis, georgicus) H. soloensis H. heidelbergensis H. sapiens neanderthalensis H. sapiens sapiens (includes idaltu) All Australopithecines All Homo erectus (includes Atapuerca, heidelbergensis, and soloensis) Early Homo (includes habilis, rudolfensis, georgicus) H. rudolfensis H. georgicus H. ergaster

N

Mean

SD

CV

Skewness

Kurtosis

Maximum

Minimum

5 4 9 6 1 9 6

445.8 431.7 503.3 508.3 450 461.2 610.3

71.84 40.4 28.39 23.38 na 49.17 62.03

16.1 9.3 5.6 4.6 na 10.6 10.2

0.938 1.569 −0.55 0.298 na 1.059 −0.624

−1.28 2.45 0.51 0.94 na 0.81 0.34

550 490 545 545 na 560 687

387 400 450 475 na 400 510

20

951.8

113.5

11.9

0.131

0.62

1220

727

7 12 28 23

1155.8 1262.8 1427.2 1496.5

83.56 99.62 150.55 111.09

7.2 7.9 10.5 7.4

−0.744 0.856 −0.005 −0.336

−0.14 −0.25 −1.27 0.46

1250 1450 1700 1730

1013 1150 1200 1250

28 41

467.4 1092.9

51.29 177.6

11 16.2

0.104 −0.585

−1.14 0.72

560 1450

387 727

13

697.8

104.03

14.9

−0.189

−0.97

848

510

2 2 3

788.5 715 800.7

51.6 91.9 49.1

6.6 12.8 6.1

na na −0.304

na na na

825 780 848

752 650 750

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