Author(s): Beaudet A.; Bruxelles L.; Stratford D.; Clarke R.J.; Heaton J.L.; Pickering T.R.; Carlson K.J.; Crompton R.; Jashashvili T.; Jakata K.; Hoffman J.; Dhaene J.
Source: American Journal of Physical Anthropology; Mar 2019; vol. 168 ; p. 14-15
Publication Date: Mar 2019
Publication Type(s): Conference Abstract
Available at American Journal of Physical Anthropology – from Wiley Online Library Full Collection
Abstract:The Australopithecus specimen StW 573 (“Little Foot”) was discovered in 1997 in Member 2 of the Sterkfontein Formation (South Africa). Besides representing one of the oldest examples of Australopithecus in the southern African fossil record, the StW 573 skeleton is remarkable for its exceptional degree of preservation and completeness. In this regard, StW 573 offers the opportunity to shed new light on the poorly known postcranial anatomy and locomotor behaviour of Pliocene hominins. In particular, meticulous excavation and high-resolution micro-CT scanning of the skull revealed a nearly complete first cervical vertebra cemented by breccia to the back of the maxilla. The atlas of StW 573 is missing only the left transverse process and exhibits slight damage to the tip of the right transverse process. Comparative morphological study indicates a combination of human-like (e.g., mildly concave superior articular facets, posterior expansion of the vertebral canal), ape-like (e.g., prominent anterior tubercle, supero-inferior widening of the posterior arch) and unexpected (i.e., absence of prominent tubercles for attachment of the transverse ligament) traits. Since cervical vertebrae play a major role in directing and stabilizing head movement and because they rarely preserve in the fossil record (i.e., this is the first atlas from Sterkfontein), ongoing comparative morphometric analyses of the atlas of StW 573 will provide new evidence for reconstructing early hominin posture and locomotion.