Department of Anthropology, Georgia State University
Thursday All day, Clinch Concourse
Cercopithecoides williamsi from the Pliocene karstic caves of South Africa, including Sterkfontein Member 4, Sterkfontein West Pit, Bolt’s Farm and Makapansgat, has been previously described as a terrestrial colobine monkey. This characterization differs from other Plio-Pleistocene cercopithecid monkeys which are allocated to the Papionini. In order to infer the dietary proclivities of Cercopithecoides williamsi (n = 17) we utilize low-magnification stereomicroscopy at 35x using an ocular reticle and an external light source to manifest small, large and puncture pits as well as fine, coarse and hypercoarse scratches. Although additional specimens were examined, not all individuals showed evidence of dental microwear due to postmortem taphonomy. The comparative sample includes Colobus spp. (n = 8), Gorilla gorilla (n = 5), Papio ursinus (n = 35), Theropithecus gelada (n = 5). Analysis of Variance shows that the taxa can be distinguished on the basis of fine scratches (p = 0.012) and hypercoarse scratches (p = 0.031). When all scratches are compared to all pits, the 95% confidence ellipse around group centroids nearly separates Papio ursinus and Cercopithecoides williamsi while the confidence ellipse for Colobus spp. overlaps both taxa. Multivariate analyses show that Papio ursinus and Colobus spp. are distinct from Cercopithecoides williamsi due to the predominance of fine scratches in the former two and small pits and lack of fine scratches in the fossil taxon. Given its attribution to the Colobinae, we expected Cercopithecoides williamsi to align with Colobus spp. However, its inferred terrestriality may explain its distinction from extant arboreal Colobus spp.
This research was supported by a Research Professional Enhancement Grant from the Vice President for Research at Georgia State University.