A hominine hip bone, KNM-ER 3228, from East Lake Turkana, Kenya
ABSTRACT A male hominine partial hip bone, KNM -ER 3228, from East Lake Turkana , Kenya is described. In most of its features this specimen resembles modern human male hip bones. This is especially true for functional features related to weight transfer from the trunk to the pelvis and within the pelvis, and to the effective action of musculature arising from the pelvis during the performance of the modern human type of bipedalism . KNM -ER 3228 is very similar to the Olduvai Hominid 28 and the Arago XLIV hip bones, both attributed to Homo erectus .
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ABSTRACT: The fossil record of the human pelvis reveals the selective priorities acting on hominin anatomy at different points in our evolutionary history, during which mechanical requirements for locomotion, childbirth and thermoregulation often conflicted. In our earliest upright ancestors, fundamental alterations of the pelvis compared with non-human primates facilitated bipedal walking. Further changes early in hominin evolution produced a platypelloid birth canal in a pelvis that was wide overall, with flaring ilia. This pelvic form was maintained over 3-4 Myr with only moderate changes in response to greater habitat diversity, changes in locomotor behaviour and increases in brain size. It was not until Homo sapiens evolved in Africa and the Middle East 200 000 years ago that the narrow anatomically modern pelvis with a more circular birth canal emerged. This major change appears to reflect selective pressures for further increases in neonatal brain size and for a narrow body shape associated with heat dissipation in warm environments. The advent of the modern birth canal, the shape and alignment of which require fetal rotation during birth, allowed the earliest members of our species to deal obstetrically with increases in encephalization while maintaining a narrow body to meet thermoregulatory demands and enhance locomotor performance. © 2015 The Author(s) Published by the Royal Society. All rights reserved.Philosophical Transactions of The Royal Society B Biological Sciences 03/2015; 370(1663). DOI:10.1098/rstb.2014.0063 · 6.31 Impact Factor
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ABSTRACT: The morphology of the distal portion of the hominoid ulna is poorly studied despite its important functional role at the wrist joint. There are five qualitatively well-described fossil hominin distal ulnae belonging to Australopithecus afarensis and Australopithecus africanus, but there have been few efforts to quantify their morphology or relate it to their functional abilities. This article presents an effort to do so, using three-dimensional geometric morphometrics to analyze the shape of the distal ulna of the Plio-Pleistocene hominins and an extant comparative sample of great apes and humans. For the extant taxa, results show that the morphology of Pan and Pongo is distinct from that of Homo, and that these differences are likely related to climbing, clambering and below-branch suspension in the former, and the release of the limbs from locomotion and (potentially) tool manufacture in the latter. For the australopiths, results indicate that the A. afarensis sample is relatively heterogeneous. These results are driven by the morphology of A.L. 333-12, which is the largest ulna in the sample and has a unique combination of traits when compared with the other two A. afarensis specimens. Overall, the morphology of all the hominins was most consistent with the pattern displayed by extant great apes, and specifically Pan and Pongo; however, large overlap in shape in the distal ulna in the extant sample indicates that other areas of the skeleton may be more informative for functional analyses. Anat Rec, 298:195–211, 2015. © 2014 Wiley Periodicals, Inc.The Anatomical Record Advances in Integrative Anatomy and Evolutionary Biology 01/2015; 298(1). DOI:10.1002/ar.23078 · 1.53 Impact Factor
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ABSTRACT: An investigation was carried out on 12 character states often said to be autapomorphic of the neurocranium of H. erectus. The African pongids were used as the outgroup. The majority of these traits were qualitative (i.e., present or absent) and could thus be treated using the classic Hennigian method. Of these, none was autapomorphic in H. erectus. However, the occipital torus was apomorphic for H. erectus and anatomically modern H. sapiens; the neandertals and the “ante-neandertals” appear to demonstrate an autapomorphic pattern in their occipital torus. The remainder of the traits were quantitative; a Student's t with a level of significance of 0·05 was used as the point of discrimination between primitive and derived character states, although problems with this technique were noted. Of these metric character states, none was autapomorphic in H. erectus. However, one included metric trait, increased cranial vault thickness, was found to show significant statistical discrimination of H. erectus from the outgroups, the australopithecines and anatomically modern Homo sapiens. However, thickened cranial vault bone was also found in the neandertals and in most other non-modern hominids although it was generally less in these groups relative to H. erectus. The presence of thickened vault bone in these groups prevents the trait from being a H. erectus autapomorph. It was hypothesized here that cranial thickness in hominoids occurs in two ways. Increased superior vault thickness is derived for H. erectus and most other non-modern hominids. Thickness of the inferior cranium, on the other hand, reflects retained pneumatodiploic bone and is symplesiomorphic, being shared by the outgroups, the australopithecines and H. erectus. Inferior vault expansion has decreased (relative to H. erectus, the australopithecines and the outgroups) in the neandertals and most other non-modern hominids. Several hypotheses concerning the relationship of H. erectus to other hominids were tested. Among the conclusions are that on the basis of the included traits H. erectus, as presently defined and using the methodology of phylogenetic systematics, cannot be considered a valid species. It was argued, however, that the challenge to the taxon H. erectus rests less with the biological reality of such a group than with the present taxonomic configuration of middle and early upper Pleistocene hominids. It was also suggested that the neandertals, who appear to have a number of autapomorphs, should not be included within the modern species, Homo sapiens.Journal of Human Evolution 05/1991; 20(5):375–412. DOI:10.1016/0047-2484(91)90006-H · 3.87 Impact Factor