A new look at Kenyapithecus based on recent discoveries in Western Kenya

Abstract

A collection of fossil higher primate teeth from Maboko, Kenya, made in 1982 and 1983 has led to this re-assessment of the status of Kenyapithecus. In particular, it is concluded that some individuals of both Kenyapithecus africanus, and K. wickeri probably possessed large canines and that both had large third molars. This finding has a bearing on how one views the relationships of Kenyapithecus to Sivapithecines (Sivapithecus and Ramapithecus) and to the Hominidae. The re-assignment to K. wickeri of all teeth from Fort Ternan formerly identified as P. nyanzae, affects palaeoecological conclusions published recently. In addition, it is shown that none of the teeth collected at Maboko has close affinities to Proconsul, and it is considered unlikely that this taxon occurs there. On this basis, it is suggested that the Maboko postcranial bones, traditionally assigned to Proconsul nyanzae, may possibly belong to Kenyapithecus africanus and thereby acquire a fresh significance. Detailed study of the maxillae of K. africanus and K. wickeri reveals a significant number of morphological differences between the two taxa, which suggests that it may eventually be necessary to separate them at the generic level. Two size groups of dental remains assignable to Kenyapithecus occur in the Maboko Formation. A mandible in the group of smaller specimens has a canine of female morphology, which makes it more likely that the two groups represent males and females of a single sexually dimorphic taxon, K. africanus. The total number of specimens assigned to Kenyapithecus is increased from nine to seventy-two.