The first occurrence of Cainochoerus (Mammalia, Artiodactyla, Suidae) from the Upper Miocene Lemudong’o Formation, Kenya

Cainochoerus is an extinct suid (Mammalia, Artiodactyla) taxon of very small size, found in multiple late Neogene sites in southern and eastern Africa. Despite its wide geographic distribution and temporal range (ca. 10–4.4 Ma), it remains a rare taxon in eastern Africa. Here we report new dentognathic material representing the first reported occurrence of Cainochoerus from the Late Miocene (6 Ma) Lemudong’o Formation, Kenya. This includes the first known deciduous upper premolar attributed to this taxon in eastern Africa. The dental metrics are generally consistent with those attributed to Cainochoerus africanus from Langebaanweg, South Africa. The maxillary molars are closely similar in morphology to those from Lothagam, Kenya, with slight differences in the upper second molar. Because Cainochoerus africanus is the only known Late Miocene small suid in Africa, we attribute these fossils to Cainochoerus cf. africanus. This discovery adds another mammalian species to the faunal community of the Lemudong’o Formation and slightly expands the geographic range of Cainochoerus to the southern Kenyan Rift.