MOST reviewers of East African early Miocene apes have been impressed by their similarity, as an adaptive array, to living Cebidae. These apes are most frequently pictured as small to medium-sized cebid-like quadrupeds occupying arboreal1–6, fruit-and leaf-eating3,7,8, tropical rainforest9 niches. It has also been suggested that the decline in the diversity of apes in middle to late Miocene times was triggered by ecological competition from rapidly radiating cercopithecids9–11. In this report I examine the molar structure of early Miocene hominoids to see whether or not these species occupied a wide spectrum of fruit- and leaf-eating niches, similar to those of today's cercopithecids.