The 89th Annual Meeting of the American Association of Physical Anthropologists (2020)

Dental Occlusal Form and Function in Equus capensis: Evaluating a Controvertible Taxonomic Status


Archaeology, University of Cape Town

April 17, 2020 17, Platinum Ballroom Add to calendar

The extinct Giant Cape Zebra Equus capensis is characterised as a relatively long-lived species that persisted throughout the Middle-to-Late Pleistocene in South Africa, covering an important time in hominin evolution. This large equid is recorded at a variety of sites relevant to hominins; understanding these palaeoenvironments provides a framework for understanding human ecosystems. Equus capensis is typically described as a large-bodied equid with an occlusal enamel morphology that distinguished it from other contemporary equids. It is important to understand the taxonomic status of E. capensis, and especially whether multiple, unrecognized, and potentially ecologically diverse species are represented. Here we investigate occlusal enamel form and function to evaluate the taxonomic status of E. capensis, and explore its associated palaeoenvironmental conditions across South African sites (Elandsfontein, Swartkrans, Makapansgat, Gladysvale, Cave of Hearths, and more).

Geometric morphometric analysis was used to quantify occlusal enamel pattern in 117 fossil equid cheek teeth. A sample subset was also used to evaluate levels of enamel complexity to determine habitat preference and palaeo-vegetation. Additionally, a total of 550 dental specimens encompassing eight equid taxa were measured using linear measurements to evaluate overall dental size variation. Finally, mesowear analysis was performed to evaluate dietary regimes, and by extension site palaeoenvironments. No significant morphological or functional differences were found between teeth identified as E. capensis and those identified to other fossil equid species, placing the taxonomic status of E. capensis in doubt (as in aDNA studies), and suggesting that palaeoenvironmental reconstructions of these hominin sites may be flawed.

This project was funded by the National Research Foundation, the University of Cape Town and the UCT Vice-Chancellor's Research Scholarship.

Slides/Poster (pdf)