The Omo-Turkana Basin Fossil Hominins and Their Contribution to Our Understanding of Human Evolution in Africa

Evolutionary Anthropology

Volumn 20, Issue 6, 2011, Pages 264-292

  Wood, Bernard ^a   Leakey, Meave ^b  

^a GEORGE WASHINGTON UNIVERSITY   (United States)

^b STONY BROOK UNIVERSITY   (United States)

Author keywords

Australopithecus; East Africa; Homo; Paranthropus; Taxonomy

Indexed keywords

ANIMAL; ARTICLE; ETHIOPIA; EVOLUTION; FOSSIL; HOMINID; HUMAN; KENYA;

ANIMALS; BIOLOGICAL EVOLUTION; ETHIOPIA; FOSSILS; HOMINIDAE; HUMANS; KENYA;

EID: 83655172315     PISSN: 10601538     EISSN: 15206505     Source Type: Journal    
DOI: 10.1002/evan.20335     Document Type: Article

References (133)

1. Wood B. 2010. Reconstructing human evolution: achievements, challenges, and opportunities. Proc Natl Acad Sci USA 107: 8902-8909.
2. Bennett MR, Harris JWK, Richmond BG, Braun DR, Mbua E, Kiura P, 2009. Early hominin foot morphology based on 1.5-million-year-old footprints from Ileret, Kenya. Science 323: 1197-1201.
3. Tocheri MW, Orr CM, Jacofsky MC, Marzke MW. 2008. The evolutionary history of the hominin hand since the last common ancestor of Pan and Homo. J Anat 212: 544-562.
4. Alemseged Z, Wynn JG, Kimbel W, Reed D, Geraads D, Bobe R. 2005. A new hominin from the basal member of the Hadar Formation, Dikika, Ethiopia, and its geological context. J Hum Evol 49: 499-514.
5. Howell FC. 1969. Hominid teeth from White Sands and Brown Sands localities, Lower Omo Basin (Ethiopia). Quaternaria 11: 47-64.
6. Kimbel WH. 1988. Identification of a partial cranium of Australopithecus afarensis, from the Koobi Fora Formation, Kenya. J Hum Evol 17: 647-656.
7. Coffing K, Feibel C, Leakey M, Walker A. 1994. Four-million-year-old hominids from East Lake Turkana, Kenya. Am J Phys Anthropol 93: 55-65.
8. Patterson B, Behrensmeyer AK, Sill WD. 1970. Geology and fauna of a new Pliocene locality in north-western Kenya. Nature 226: 918-921.
9. Leakey MG, Feibel CS, Bernor RL, Harris JM, Cerling TE, Stewart KM, Storrs GW, Walker A, Werdelin L, Winkler AJ. 1996. Lothagam: a record of faunal change in the Late Miocene of East Africa. J Vert Paleontol 16: 556-570.
10. Hill A, Ward S. 1988. Origin of the Hominidae: the record of African large hominoid evolution between 14 my and 4 my. Am J Phys Anthropol 31: 49-83.
11. Leakey MG, Walker A. 2003. The Lothagam hominids. In: Harris J, Leakey M, editors. Lothagam: the dawn of humanity in eastern Africa. New York: Columbia University Press. p 249-258.
12. MacLatchy LM, DeSilva J, Sanders WJ, Wood B. 2010. Hominini. In: Werdelin L, Sanders WJ, editors. Cenozoic mammals of Africa. Berkeley: University of California Press. p 471-540.
13. Ward CV, Leakey MG, Brown B, Brown F, Harris J, Walker A. 1999. South Turkwel: a new Pliocene hominid site in Kenya. J Hum Evol 36: 69-95.
14. Fleagle JG, Rasmussen DT, Yirga S, Brown TM, Grine FE. 1991. New hominid fossils from Fejej, Southern Ethiopia. J Hum Evol 21: 145-152.
15. Kappelman J, Swisher CG, Fleagle JG, Yirga S, Brown T, Feseha M. 1996. Age of Australopithecus afarensis from Fejej, Ethiopia. J Hum Evol 30: 139-146.
16. Patterson B., Howells WW. 1967. Hominid humeral fragment from early Pleistocene of northwest Kenya. Science 156: 64-66.
17. Leakey MG, Feibel CS, McDougall I, Walker A. 1995. New four-million-year-old hominid species from Kanapoi and Allia Bay, Kenya. Nature 376: 565-571.
18. Leakey MG, Feibel CS, McDougall I, Ward C, Walker A. 1998. New specimens and confirmation of an early age for Australopithecus anamensis. Nature 393: 62-66.
19. White TD, WoldeGabriel G, Asfaw B, Ambrose S, Beyene Y, Bernor RL, 2006. Asa Issie, Aramis and the origin of Australopithecus. Science 440: 883-889.
20. Ward C, Leakey M, Walker A. 1999. The new hominid species Australopithecus anamensis. Evol Anthropol 7: 197-205.
21. Kimbel WH, Lockwood CA, Ward C, Leakey MG, Rak Y, Johanson DC. 2006. Was Australopithecus anamensis ancestral to Au. afarensis? A case of anagenesis in the hominin fossil record. J Hum Evol 51: 134-152.
22. Haile-Selassie Y, Saylor BZ, Deino A, Alene M, Latimer BM. 2010. New hominid fossils from Woranso-Mille (Central Afar, Ethiopia) and taxonomy of early Australopithecus. Am J Phys Anthropol 141: 406-417.
23. Harris JM, Brown FH, Leakey MG, Walker A, Leakey REF. 1988. Pliocene and Pleistocene hominid-bearing sites from west of Lake Turkana, Kenya. Science 239: 27-33.
24. Brown B, Brown FH, Walker A. 2001. New hominids from the Lake Turkana Basin, Kenya. J Hum Evol 41: 29-44.
25. Kimbel WH, Delezene LK. 2009. "Lucy" redux: a review of research on Australopithecus afarensis. Am J Phys Anthropol 140: 2-48.
26. Leakey MG, Spoor F, Brown FH, Gathogo PN, Kiarie C, Leakey LN, 2001. New hominin genus from eastern Africa shows diverse middle Pliocene lineages. Nature 410: 433-440.
27. White T. 2003. Early hominids - diversity or distortion? Science 299: 1994-1997.
28. Spoor F, Leakey MG, Leakey LN. 2010. Hominin diversity in the Middle Pliocene of eastern Africa: the maxilla of KNM-WT 40000. Philos Trans R Soc Lond B Biol Sci 365: 3377-3388.
29. Leakey LSB, Tobias PV, Napier JR. 1964. A new species of the genus Homo from Olduvai Gorge. Nature 202: 7-9.
30. Tobias PV. 1967. Olduvai Gorge, vol 2. The cranium and maxillary dentition of Australopithecus (Zinjanthropus) boisei. New York: Cambridge University Press.
31. Robinson JT. 1960. An alternative interpretation of the supposed giant deciduous hominid tooth from Olduvai. Nature 185: 407-408.
32. Tobias PV. 1965. Early man in East Africa. Science 149: 22-33.
33. Day MH. 1969. Femoral fragment of a robust australopithecine from Olduvai Gorge, Tanzania. Nature 221: 230-233.
34. Carney J, Hill A, Miller JA, Walker AC. 1971. Late australopithecine from Baringo District, Kenya. Nature 230: 509-514.
35. Szalay FS. 1971. Biological level of organization of the Chesowanja robust australopithecine. Nature 234: 229-230.
36. Howell FC. 1978. Hominidae. In: Maglio VJ, Cooke HBS, editors. Evolution of African mammals. Cambridge: Harvard University Press. p 154-248.
37. Wood BA. 1991. Koobi Fora Research Project, vol 4. Hominid cranial remains. Oxford: Clarendon Press.
38. Gowlett JAJ, Harris JWK, Walton D, Wood BA. 1981. Early archaeological sites, hominid remains and traces of fire from Chesowanja, Kenya. Nature 294: 125-129.
39. Suwa G, Asfaw B, Beyene Y, White T, Katoh S, Nagaoka S, 1997. The first skull of Australopithecus boisei. Nature 389: 489-492.
40. Howell FC. 1969. Remains of Hominidae from Pliocene/Pleistocene formations in the Lower Omo Basin, Ethiopia. Nature 223: 1234-1239.
41. Coppens Y. 1978. Evolution of the hominids and of their environment during the Plio-Pleistocene in the lower Omo Valley, Ethiopia. In: Bishop WW, editor. Geological background to fossil man. Edinburgh: Scottish Academic Press. p 499-506.
42. Coppens Y. 1980. The differences between Australopithecus and Homo: preliminary conclusions from the Omo research expedition's studies. In: Konigsson L-K, editor. Current argument on early man. Oxford: Pergamon. p 207-225.
43. Coppens Y, Sakka M. 1983. Un nouveau crane d'australopitheque: evolutive morphogenese du cranie et anthropogenese. Paris: CNRS. p 185-194.
44. Alemseged Z, Coppens Y, Geraads D. 2002. Hominid cranium from Omo: description and taxonomy of Omo-323-1976-896. Am J Phys Anthropol 117: 103-112.
45. Leakey REF, Walker A. 1988. New Australopithecus boisei specimens from East and West Lake Turkana, Kenya. Am J Phys Anthropol 76: 1-24.
46. Feibel CS, Brown FH, McDougall I. 1989. Stratigraphic context of fossil hominids from the Omo group deposits: northern Turkana Basin, Kenya and Ethiopia. Am J Phys Anthropol 78: 595-622.
47. Brown B, Walker A, Ward CV, Leakey REF. 1993. New Australopithecus boisei calvaria from East Lake Turkana, Kenya. Am J Phys Anthropol 91: 137-159.
48. Prat S, Brugal J-P, Roche H, Texier P-J. 2003. Nouvelles découvertes de dents d'hominidés dans le membre Kaitio de la formation de Nachukui (1.65-1.9 Ma), Ouest du lac Turkana (Kenya). CR Palevol 2: 685-693.
49. Wood BA, Constantino P. 2007. Paranthropus boisei: fifty years of evidence and analysis. Am J Phys Anthropol 50: 106-132.
50. De Lumley MA, Marchal F. 2004. Les Restes d'hominidés du site de Fejej FJ-1. In: De Lumley H, Beyene Y, editors. Les sites préhistoriques de la région de Fejej, Sud-Omo, Éthiopie, dans leur context stratigraphique et paléontologique. Paris: Editions Recherche sur Les Civilisations. p 341-383.
51. Arambourg C, Coppens Y. 1968. Decouverte d'un australopithecien nouveau dans les gisements de l'Omo (Ethiopie). S Afr J Sci 64: 58-59.
52. Walker AC, Leakey RE, Harris JM, Brown FH. 1986. 2.5-Myr Australopithecus boisei from west of Lake Turkana, Kenya. Nature 322: 517-522.
53. Suwa G. 1988. Evolution of the "robust" australopithecines in the Omo succession: evidence from mandibular premolar morphology. In: Grine FE, editor. Evolutionary history of the "robust" australopithecines. New York: Aldine de Gruyter. p 199-222.
54. Rak Y, Kimbel WH. 1991. On the squamosal suture of KNM-WT 17000. Am J Phys Anthropol 85: 1-6.
55. Rak Y, Kimbel WH. 1993. Reply to Drs. Walker, Brown and Ward. Am J Phys Anthropol 90: 506-507.
56. Walker A, Brown B, Ward SC. 1993. Squamosal suture of cranium KNM-WT 17000. Am J Phys Anthropol 90: 501-505.
57. 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.
58. Kullmer O, Sandrock O, Abel R, Schrenk F, Bromage TG, Juwayeyi YM. 1999. The first Paranthropus from the Malawi Rift. J Hum Evol 37: 121-127.
59. Harrison T. 2011. Hominins from the Upper Laetolil and Upper Ndolanya Beds, Laetoli. In: Harrison T, editor. Paleontology and geology of Laetoli: human evolution in context. New York: Springer Dordrecht. p 141-188.
60. Leakey LSB, Tobias PV, Napier JR. 1964. A new species of the genus Homo from Olduvai Gorge. Nature 202: 7-9.
61. Leakey MD. 1971. Olduvai Gorge, vol 3. Excavations in Beds I and II, 1960-1963. Cambridge: Cambridge University Press.
62. Johanson D, Masao F, Eck G, White T, Walter R, Kimbel W. 1987. New partial skeleton of Homo habilis from Olduvai Gorge, Tanzania. Nature 327: 205-209.
63. Hartwig-Scherer S, Martin RD. 1991. Was 'Lucy' more human than the 'child'? Observations on early hominid postcranial skeletons. J Hum Evol 21: 439-449.
64. Reno PL, DeGusta D, Serrat MA, Meindl RS, White TD, Eckhardt RB, 2005. Plio-Pleistocene hominid limb proportions: evolutionary reversals or estimation errors? Curr Anthropol 46: 575-588.
65. Richmond BG, Aiello LC, Wood BA. 2002. Early hominin limb proportions. J Hum Evol 43: 529-548.
66. Blumenschine RJ, Peters CR, Masao FT, Clarke RJ, Deino A, Hay RL, 2003. Late Pliocene Homo and hominid land use from western Olduvai Gorge, Tanzania. Science 299: 1217-1221.
67. Hughes AR, Tobias PV. 1977. A fossil skull probably of the genus Homo from Sterkfontein, Transvaal. Nature 265: 310-312.
68. Grine FE, Demes B, Jungers WL, Cole TM. 1993. Taxonomic affinity of the early Homo cranium from Swartkrans, South Africa. Am J Phys Anthropol 92: 411-426.
69. Kimbel WH, Walter RC, Johanson DC, Reed KE, Aronson JL, Assefa Z, 1996. Late Pliocene Homo and Oldowan tools from the Hadar Formation (Kadar Hadar Member), Ethiopia. J Hum Evol 31: 549-561.
70. Kimbel WH, Johanson DC, Rak Y. 1997. Systematic assessment of a maxilla of Homo from Hadar, Ethiopia. Am J Phys Anthropol 103: 235-262.
71. Hill A. 1985. Early hominid from Baringo, Kenya. Nature 315: 222-224.
72. Curnoe D, Tobias PV. 2006. Description, new reconstruction, comparative anatomy, and classification of the Sterkfontein Stw 53 cranium, with discussions about the taxonomy of other southern African early Homo remains. J Hum Evol 50: 36-77.
73. Tobias PV, von Koenigswald GHR. 1964. A comparison between the Olduvai hominids and those of Java and some implications for hominid phylogeny. Nature 204: 515-518.
74. Vekua A, Lordkipanidze D, Rightmire GP, Agustí J, Ferring R, Maisuradze G, 2002. A new skull of early Homo from Dmanisi, Georgia. Science 297: 85-89.
75. Rightmire GP, Lordkipanidze D, Vekua A. 2006. Anatomical descriptions, comparative studies and evolutionary significance of the hominin skulls from Dmanisi, Republic of Georgia. J Hum Evol 50: 115-141.
76. Lordkipanidze D, Jashashvili T, Vekua A, Ponce de León MS, Zollikofer CPE, Rightmire GP, 2007. Postcranial evidence from early Homo from Dmanisi, Georgia. Nature 449: 305-310.
77. Boaz NT, Howell FC. 1977. A gracile hominid cranium from upper member G of the Shungura Formation, Ethiopia. Am J Phys Anthropol 46: 93-108.
78. Coppens Y. 1980. The differences between Australopithecus and Homo; preliminary conclusions from the Omo Research Expedition's studies. In: Königsson LK, editor. Current argument on early man. Oxford: Pergamon. p 207-225.
79. Suwa G, White TD, Howell FC. 1996. Mandibular postcanine dentition from the Shungura Formation, Ethiopia: crown morphology, taxonomic allocations and Plio-Pleistocene hominid evolution. Am J Phys Anthropol 101: 247-282.
80. Prat S, Brugal JP, Tiercelin JJ, Barrat JA, Bohn M, Delagnes A, 2005. First occurrence of early Homo in the Nachukui Formation (West Turkana, Kenya) at 2.3-2.4 Myr. J Hum Evol 49: 230-240.
81. Tobias PV. 1991. Olduvai Gorge, vol 4. The skulls, endocasts and teeth of Homo habilis. Cambridge: Cambridge University Press.
82. Groves CP. 1989. A theory of human and primate evolution. Oxford: Clarendon Press.
83. Bromage TG, Schrenk F, Juwayeyi YM. 1995. Paleobiogeography of the Malawi Rift: age and vertebrate paleontology of the Chiwondo Beds, northern Malawi. J Hum Evol 28: 37-57.
84. Groves CP, Mazák, V. 1975. An approach to the taxonomy of the Hominidae: gracile Villafranchian hominids of Africa. Casopis pro mineralogii a geologii 20: 225-247.
85. Wood BA. 1994. Taxonomy and evolutionary relationships of Homo erectus. Cour Forsch Inst Senckenberg 171: 59-165.
86. Brown F, Harris J, Leakey REF, Walker AC. 1985. Early Homo erectus skeleton from west Lake Turkana, Kenya. Nature 316: 788-792.
87. Dean MC, Smith BH. 2009. Growth and development of the Nariokotome youth, KNM-WT 15000. In: Grine FE, Fleagle JG, Leakey RE, editors. The first humans: origin and early evolution of the genus Homo. New York: Springer Dordrecht. p 101-120.
88. Dean C. 2010. Retrieving chronological age from dental remains of early fossil hominins to reconstruct human growth in the past. Philos Trans R Soc Lond B Biol Sci 335: 3397-3410.
89. Dean C, Leakey MG, Reid D, Schrenk F, Schwartz GT, Stringer C, 2001. Growth processes in teeth distinguish modern humans from Homo erectus and earlier hominins. Nature 414: 628-631.
90. Walker A, Leakey REF. 1993. The Nariokotome Homo erectus skeleton. Cambridge: Harvard University Press.
91. Ohman JC, Wood C, Wood B, Crompton RH, Günther MM, Yu L, 2002. Stature-at-death of KNM-WT 15000. J Hum Evol 17: 129-141.
92. Graves R, Lupo A, McCarthy R, Wescott D, Cunningham D. 2010. Just how strapping was KNM-WT 15000? J Hum Evol 59: 542-554.
93. Spoor F, Leakey MG, Gathogo PN, Brown FH, Antón SC, McDougall I, 2007. Implications of new early Homo fossils from Ileret, east of Lake Turkana, Kenya. Nature 448: 688-691.
94. Woodward AS. 1921. A new cave man from Rhodesia, South Africa. Nature 108: 371-372.
95. Dreyer TF. 1935. A human skull from Florisbad, Orange Free State, with a note on the endocranial cast by C.U. Ariens Kappers. Proc R Acad Sci Amst 38: 119-128.
96. McBrearty S, Brooks AS. 2000. The revolution that wasn't: a new interpretation of the origin of modern human behavior. J Hum Evol 39: 453-563.
97. Bräuer, G. 2008. The origin of modern anatomy: by speciation or intraspecific evolution? Evol Anthropol 17: 22-37.
98. Bräuer G, Leakey REF, Mbua E. 1992. A first report on the ER-3884 cranial remains from Ileret/ East Turkana, Kenya. In: Bräuer G, Smith FH, editors. Continuity or replacement? Controversies in Homo sapiens evolution. Rotterdam: A. A. Balkema. p 111-119.
99. Bräuer G, Leakey REF. 1986. The ES-11693 cranium from Eliye Springs, West Turkana, Kenya. J Hum Evol 15: 289-312.
100. Rightmire G. 2008. Homo in the middle Pleistocene: hypodigms, variation, and species recognition. Evol Anthropol 17: 8-21.
101. Rightmire GP. 2009. Middle and later Pleistocene hominins in Africa and Southwest Asia. Proc Nat Acad Sci USA 106: 16046-16050.
102. Bräuer G, Yokoyama Y, Falguères C, Mbua E. 1997. Modern human origins backdated. Nature 386: 337-338.
103. Tattersall I, Schwartz JH. 2008. The morphological distinctiveness of Homo sapiens and its recognition in the fossil record: clarifying the problem. Evol Anthropol 17: 49-54.
104. Howells WW. 1973. Cranial variation in man: a study by multivariate analysis of patterns of difference among recent human populations. Cambridge: Harvard University Press.
105. Howells WW. 1989. Skull shapes and the map: craniometric analyses in the dispersion of modern Homo. Cambridge: Harvard University Press.
106. Lahr MM. 1996. The evolution of modern human diversity: a study of cranial variation. Cambridge: Cambridge University Press.
107. Spoor FS, O'Higgins P, Dean C, Lieberman DE. 1999. Anterior sphenoid in modern humans. Nature 397: 572.
108. Lieberman DE, McBratney BM, Krovitz G. 2002. The evolution and development of cranial form in Homo sapiens. Proc Nat Acad Sci USA 99: 1134-1139.
109. Fleagle, JG, editor. 2008. Modern human origins in Africa. Evol Anthropol 17: 1-80.
110. Kieser J. 1990. Human adult odontometrics: the study of variation in adult tooth size. Cambridge: Cambridge University Press.
111. Scott GR, Turner CG. 1997. The anthropology of modern human teeth: dental morphology and its variation in recent human populations. Cambridge: Cambridge University Press.
112. Irish JD, Guatelli-Steinberg D. 2003. Ancient teeth and modern human origins: an expanded comparison of African Plio-Pleistocene and recent world dental samples. J Hum Evol 45: 113-144.
113. Leakey REF. 1969. Early Homo sapiens remains from the Omo River region of south-west Ethiopia: faunal remains from the Omo Valley. Nature 222: 1132-1133.
114. Day MH. 1969. Omo human skeletal remains. Nature 222: 1135-1138.
115. Pearson OM, Royer DF, Grine FE, Fleagle JG. 2008. A description of the Omo I postcranial skeleton, including newly discovered fossils. J Hum Evol 55: 421-437.
116. McDougall I, Brown FH, Fleagle JG. 2005. Stratigraphic placement and age of modern humans from Kibish, Ethiopia. Nature 433: 733-736.
117. Hay RL. 1970. The KBS tuff controversy may be ended. Nature 284: 401.
118. Brown FH. 1988. Development of Pliocene and Pleistocene chronology of the Turkana Basin, East Africa, and its relation to other sites. In: Corruccini RS, Ciochon RL, editors. Integrative pathways to the past. Englewood Cliffs, NJ: Prentice-Hall. p 285-312.
119. Brown andMcDougall (this issue).
120. Wood BA, Wood CW, Konigsberg LW. 1994. Paranthropus boisei: an example of evolutionary stasis? Am J Phys Anthropol 95: 117-136.
121. Grausz HM, Leakey REF, Walker AC, Ward CV. 1988. Associated cranial and postcranial bones of Australopithecus boisei. In: Grine FE, editor. Evolutionary history of the "robust" australopithecines. New York: Aldine de Gruyter. p 127-132.
122. Richmond BG, Harris JWK, Mbua E, Braun DR, Bamford M, 2009. A new hominin upper limb skeleton from Ileret, Kenya. PaleoAnthropol: A31.
123. Cerling TE, Mbua M, Kirera FF, Manthi FK, Grine FG, Leakey MG. 2011. Diet of Paranthropus boisei in the early Pleistocene of East Africa. Proc Natl Acad Sci USA 108: 9337-9341.
124. Cerling TE, Wynn JG, Andanje SA, Bird MI, Korir DK, Levin NE, 2011. Woody cover and hominid environments in the past 6 million years. Nature 476: 51-56.
125. Levin NE, Thure CE, Passey BH, Harris JM, Ehleringer JR. 2011. A stable isotope aridity index for terrestrial environments. Proc Natl Acad Sci USA 103: 11201-11205.
126. Leakey REF. 1970. New hominid remains and early artefacts from northern Kenya: fauna and artifacts from a new Plio-Pleistocene locality near Lake Rudolf in Kenya. Nature 226: 223-224.
127. Leakey REF. 1971. Further evidence of Lower Pleistocene hominids from East Rudolf, North Kenya. Nature 231: 241-245.
128. Leakey REF. 1972. Further evidence of Lower Pleistocene hominids from East Rudolf, North Kenya, 1971. Nature 237: 264-269.
129. Leakey REF. 1973. Evidence for an advanced Plio-Pleistocene hominid from East Rudolf, Kenya. Nature 242: 447-450.
130. Leakey REF. 1974. Further evidence of Lower Pleistocene hominids from East Rudolf, North Kenya, 1973. Nature 248: 653-656.
131. Leakey REF, Walker AC. 1976. Australopithecus, Homo erectus and the single species hypothesis. Nature 261: 572-574.
132. Alexeev V. 1986. The origin of the human race. Moscow: Progress.
133. Smith RJ. 2005. Species recognition in paleoanthropology: implications of small sample sizes. In: Lieberman DE, Smith RJ, Kelley J, editors. Interpreting the past: essays on human, primate, and mammal evolution in honor of David Pilbeam. Boston: Brill Academic Publishers. p 207-219.