A partial hominoid skeleton just older than 15 million years from sediments in the Tugen Hills of north central Kenya mandates a revision of the hominoid genus Kenyapithecus, a possible early member of the great ape-human clade. The Tugen Hills specimen represents a new genus, which also incorporates all material previously referable to Kenyapithecus africanus. The new taxon is derived with respect to earlier Miocene hominoids but is primitive with respect to the younger species Kenyapithecus wickeri and therefore is a late member of the stem hominoid radiation in the East African Miocene.