Dental metrics of Sahelanthropus tchadensis: A comparative analysis with apes and Plio-Pleistocene hominins

Abstract

Since discovery and description of the species, Sahelanthropus tchadensis has been at the centre of a great discussion around its classification as a hominin – the first of our lineage – or an ape. Many studies have been conducted in order to clarify this question, especially studies based on the morphology of the cranium and the post-cranial remains. In this study, we analysed the posterior dentition of S. tchadensis in relation to those of other hominins and chimpanzees, using a multivariate comparative metric analysis. Our results suggest that the posterior dentition of the Chad material lies in the range of well-established early Plio-Pleistocene hominins, supporting its classification as part of the hominin lineage.

Significance:

• The subject investigated in this study is important to the understanding of the first steps of human evolution.
• Much has been discussed about this Chadian species. Some believe it is the first hominin, others believe it is an ape.
• This study shows that the posterior dentition of tchadensis does not preclude it from being a hominin.