The permanent dentition and phylogenetic position of Victoriapithecus from Maboko Island, Kenya

Abstract

Abstract More than 800 cercopithecoid permanent teeth collected since 1973 at Maboko Island are described. The 15 million-year-old fossils are attributed to a single paleospecies Victoriapithecus macinnesi. Criteria previously used to separate the 59 Victoriapithecus teeth known from Maboko before 1973 into two species, one with colobine and the other with cercopithecine affinities, are shown to be invalid. V. macinnesi differs from extant cercopithecoids in having M1-M3 cristae obliquae and M1/M2 hypoconulids that are differentially expressed across the molar row, being more common on mesial than distal teeth. The species is similar to extant Macaca in having a high degree of M3 size variation that may be related to sexual dimorphism. In contrast, I1-M2 size variation is similar to that observed for most extant cercopithecoid species. Phylogenetic comparison of Victoriapithecus and Prohylobates indicates that although the two genera are distinct, they share a unique combination of primitive catarrhine and derived cercopithecoid dental traits. Colobinae and Cercopithecinae share at least three and probably five traits that are derived relative to the Miocene cercopithecoids. It is concluded that the Miocene and more recent Old World monkeys represent mutual sister-groups with Prohylobates and Victoriapithecus belonging to the family Victoriapithecidae and Colobinae and Cercopithecinae to the family Cercopithecidae.