The late Middle Pleistocene upper third molar from Florisbad: metrics and morphology

Abstract

In the early 1930s an upper right third molar (M³) together with a calotte and fragmented facial bones of an adult fossil hominin was recovered during excavations at Florisbad. The M³ is one of the few well-dated teeth associated with cranial remains from the late Mid-Pleistocene in southern Africa and as such provides a valuable addition to the fossil dental record of this region. Here we provide a detailed description of the tooth based on standard measurements and 3D images derived from high resolution micro-high resolution micro-focus X-ray tomography. Our results show that the Florisbad M³ falls within the size range of African Homo erectus. It is slightly larger than other peri-contemporary M³s known from Africa that date from the Middle to Late Pleistocene. Like them, however, it also falls within the size range of recent, large-toothed African populations. These results suggest the maintenance of selective pressures favouring large teeth in some African populations until the present.

Keywords:

• third molar
• micro-tomography
• late Mid-Pleistocene Homo
• South Africa fossil teeth

ACKNOWLEDGEMENTS

This study was supported in part by a grant from The Hebrew University of Jerusalem to P. Smith. P. Smith thanks the director and staff of the Natural History Museum, London for access to the Kabwe specimen and the National Museum, Bloemfontein for facilitating the examination of the Florisbad specimen and Holocene collections. We thank the DST-NRF for sponsoring the micro-focus X-ray tomography facility located at Necsa.