A reassessment of the phylogenetic relationships of Oreopithecus bambolii gervais

In recent years there have been renewed attempts to elucidate the phylogenetic affinities and taxonomic status of Oreopithecus bambolii from the late Miocene of Europe. The majority of previous workers who have studied the material have concluded that it represents a hominoid primate, albeit a rather specialized one. Several recent workers have revived the earlier suggestion that Oreopithecus may be a cercopithecoid primate, based mainly on presumed synapomorphies of the dentition. Although there are some general structural similarities between the cheek teeth of Oreopithecus and those of Old World monkeys, comparisons indicate that this resemblance is likely to be due to functional convergence, related to dietary similarities, rather than due to a close phyletic relationship. The cranio-dental features of Oreopithecus appear to be a combination of primitive catarrhine characters and autapomorphies. Much more informative evidence for determining the phyletic affinities of Oreopithecus is provided by the postcranial skeleton. Oreopithecus shares with the living hominoids a unique range of derived catarrhine features of the postcranium that are so detailed that there seems little possibility that they could have been developed independently in the two taxa. The present evidence best supports the conclusion that Oreopithecus has its closest affinities with the living hominoids. However, the relationships of Oreopithecus to taxa within the Hominoidea have proved difficult to ascertain, owing to a lack of synapomorphies with living representatives of the superfamily. In view of the uniquely derived facial characteristics of Oreopithecus bambolii, the species clearly warrants inclusion in a distinct hominoid family, the Oreopithecidae.