New species of Cercopithecoides from Haasgat, North West Province, South Africa

Analyses of new cercopithecid fossil specimens from the South African site of Haasgat point to craniofacial affinities with the genus Cercopithecoides. Detailed metric and non-metric comparisons with South African Cercopithecoides williamsi, and other East African Cercopithecoides species, Cercopithecoides kimeui, Cercopithecoides meaveae, Cercopithecoides kerioensis, and Cercopithecoides alemyehui demonstrate that the Haasgat fossils have distinct craniofacial morphology and dental metrics. Specifically, material from Haasgat probably represents one of the smaller Cercopithecoides, differing from the others in its particular suite of features that vary within the genus. It is unique in its more vertical ramus, associated with a relatively lengthened mandibular body. Haasgat Cercopithecoides has a particularly narrow interorbital region between relatively larger ovoid orbits, with articulation of the maxillary bones at a suture above the triangular nasal bones. Furthermore, the maxillary arcade is more rounded than other Cercopithecoides, converging at the M² and M³. The conclusion drawn from this analysis is that the Pleistocene Haasgat fossils are colobines representing a distinct taxon of Cercopithecoides, Cercopithecoides haasgati, thus adding a second species of the genus to southern Africa.