A hominin first rib discovered at the Sterkfontein Caves, South Africa.

Date
2016-05
Authors
Tawane, G.
Garcia-Martinez, D.
Eyre, J.
Bastir, M.
Berger, L.R.
Schmid, P.
Nalla, S.
Williams, S.A.
Journal Title
Journal ISSN
Volume Title
Publisher
Academy of Science of South Africa (ASSAf)
Abstract
First ribs - the first or most superior ribs in the thorax - are rare in the hominin fossil record, and when found, have the potential to provide information regarding the upper thorax shape of extinct hominins. Here, we describe a partial first rib from Member 4 of the Sterkfontein Caves, South Africa. The rib shaft is broken away, so only the head and neck are preserved. The rib is small, falling closest to small-bodied Australopithecus first ribs (AL 288-1 and MH1). Given that it was recovered near the StW 318 femur excavation, which also represents a small individual, we suggest that the two may be associated. Three-dimensional geometric morphometric analyses were used to quantify the rib fragment morphology and compare it to extant hominoid and other fossil hominin ribs. While only the proximal end is preserved, our analyses show that South African Australopithecus share derived features of the proximal first rib more closely resembling A. afarensis and later hominins than great apes.
Description
Keywords
Australopithecus africanus, Gauteng Province, Geometric morphometrics, Rib cage, Upper thorax
Citation
Tawane,G. et al. 2016.A hominin first rib discovered at the Sterkfontein Caves, South Africa.South African Journal of Science 112 (5-6): Article number 112.