Hominin lower limb bones from Sterkfontein Caves, South Africa (1998–2003 excavations)

Ron J. Clarke,A.J. Heile,Dominic Stratford,Jason L. Heaton,Travis Rayne Pickering

doi:10.17159/sajs.2021/6758

Abstract

We describe late Pliocene and early Pleistocene hominin fossils from Sterkfontein Caves (South Africa), including two femoral specimens, as well as a partial tibia and a partial fibula. The fossils are likely assignable to Australopithecus africanus and/or Australopithecus prometheus and the morphology of each corroborates previous interpretations of Sterkfontein hominins as at least facultative bipeds. Significance:  A recent series of papers by our research team describes the morphology of a hominin skeleton from Sterkfontein Caves (South Africa), nicknamed ‘Little Foot’. Based on its unique skull morphology, R.J. Clarke, the skeleton’s discoverer, places it in the species Australopithecus prometheus, as distinct from the better-known and co-occurring Australopithecus africanus. Here we describe additional hominin thigh and leg fossils from Sterkfontein that, when considered in a comparative context, support the hypothesis that there was significant (probably interspecific) variation in South African hominin postcranial morphology during the late Pliocene and early Pleistocene.

Highlights

A long history of palaeoanthropological research at Sterkfontein Caves (Gauteng, South Africa), starting in 1936, has yielded a massive store of hominin fossils.[1,2,3,4,5] As one in a series of papers, we report here on four previously undescribed hominin fossils excavated by R.J.C. between 1998 and 2003
We are troubled by the fact that many disputants in these debates misunderstand or ignore the completely salient possibility that the Sterkfontein Member 4 hominin postcranial collection samples at least two coeval species, A. africanus and A. prometheus, as is the case for the large craniodental sample of hominin fossils from that depositional unit.[5,6,17,18,19]
Kibii and Clarke[57] suggested that the pelves of the partial Sterkfontein Member 4 skeletons, Sts 14 and StW 431, do not necessarily sample the same species. This issue has been clarified recently with the cleaning and reconstruction of the StW 573 skeleton of a female A. prometheus from Sterkfontein Member 262, which has a pelvis of similar size and morphology as that of the StW 431 male skeleton

Summary

Introduction

A long history of palaeoanthropological research at Sterkfontein Caves (Gauteng, South Africa), starting in 1936, has yielded a massive store of hominin fossils.[1,2,3,4,5] As one in a series of papers, we report here on four previously undescribed hominin fossils excavated by R.J.C. between 1998 and 2003. Those other papers present descriptions and interpretations of sizeable samples of teeth[6] and of axial and upper limb bones[7,8].

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Results

Discussion

Conclusion