COMPARATIVE SCORING OF OREOPITHECUS BAMBOLII AND EXTANT AFRICAN APE MAXILLARY MOLARS

Late Miocene Oreopithecus bambolii molars arecharacterized feature tall crested molars, which resemble the bilophodonty of cercopithecids while retaining morphology similar to the apes by exhibiting a larger paracone and protocone relative to the metacone and hypocone. Based on convergent adaptations related to folivorous diets, Oreopithecus should align more with Gorilla gorilla, compared to Pan troglodytes. Using Pilbrow’s Great Ape Dental Scoring System, we examined the morphological features of the first maxillary molars of Oreopithecus bambolii specimen IGF 11778, Pan troglodytes (n = 16) and Gorilla gorilla (n = 11). On the first scores axis, all taxa are largely separated with minor overlap between Pan and Gorilla. Oreopithecus is situated on the negative extreme of the first axis (86.1% of variance) based on the scores for the sulcus obliquus, and to a lesser extent, by the crista obliqua whereas Gorilla is polarized on the positive end by its mesial fovea and centroconule scores, followed by the anterior transverse crest, whereas Pan falls between these extremes. On the second axis (13.6% of variance), Oreopithecus has overlap with Gorilla based on the crista obliqua and anterior transverse crest, whereas Pan, and some Gorilla, are projected in a negative direction from their distal fovea, anterior transverse crest and hypocone essential crest scores. Oreopithecus is more distinctive from African apes than Pan and Gorilla are from each other. This taxon resembles Gorilla in such traits as the sulcus obliquus and crista obliqua, traits that create a more complex molar topography and likely assist in processing folivorous diets