Paleobiology of the oligopithecines, the earliest known anthropoid primates

Abstract

Anthropoid primates of the subfamily Oligopithecinae are late Eocene in age, and have a known distribution of Northeast Africa and the Arabian Peninsula. Body sizes of the three known oligopithecine species are estimated from allometric molar size regressions to be 700-1000 g for Oligopithecus savagei, 600-900 g for Catopithecus browni, and 500 g for the least well-known and smallest species, Proteopithecus sylviae. Occlusal features of the molar teeth, considered in conjunction with body size, suggest that all three species were frugivorous and insectivorous. The orbital size of Catopithecus indicates a diurnal activity cycle. A relatively broad interobital region in this species may indicate prosimian-like or callitrichid-like olfactory adaptations. Structural features of the crushed skull suggest that Catopithecus had a smaller cranial capacity than those of extant anthropoids with a similar body size. Fossil plants and birds from localities yielding oligopithecines suggest a wet, warm, tropical, forested, swampy environment. These paleobiological inferences about the extinct oligopithecines are discussed in relation to questions about primate adaptations near the prosimian-anthropoid transition. © 1992 Plenum Publishing Corporation.