''Rhinocolobus'' is an extinct genus of monkey closely related to modern

colobus monkeys Black-and-white colobuses (or colobi) are Old World monkeys of the genus ''Colobus'', native to Africa. They are closely related to the red colobus monkeys of genus '' Piliocolobus''. There are five species of this monkey, and at least eight subs ...

. It lived in eastern

Africa Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...

during the

Plio-Pleistocene The Plio-Pleistocene is an informally described geological pseudo-period, which begins about 5 million years ago (Mya) and, drawing forward, combines the time ranges of the formally defined Pliocene and Pleistocene epochs—marking from about 5&nbs ...

, existing as recently as 1.5 million years ago.

Taxonomy

Fossils of ''Rhinocolobus'' were found in

Shungura formation The Shungura Formation is a stratigraphic formation located in the Omo River (Ethiopia), Omo river basin in Ethiopia. It dates to the Pliocene, Late Pliocene to Early Pleistocene. Oldowan tools have been found in the formation, suggesting early us ...

and Usno formation surrounding the Omo river valley and the Hadar formation surrounding the

Afar depression The Afar Triangle (also called the Afar Depression) is a geological depression caused by the Afar Triple Junction, which is part of the Great Rift Valley in East Africa. The region has disclosed fossil specimens of the very earliest hominins; tha ...

Ethiopia Ethiopia, , om, Itiyoophiyaa, so, Itoobiya, ti, ኢትዮጵያ, Ítiyop'iya, aa, Itiyoppiya officially the Federal Democratic Republic of Ethiopia, is a landlocked country in the Horn of Africa. It shares borders with Eritrea to the ...

. It has been closely allied with living colobus monkeys as well as the extinct '' Paracolobus''.

Description

''Rhinocolobus'' was larger than any living colobus monkey, and also displayed sexual dimorphism. Fossils of males have been estimated to weigh , while females have been estimated at only . It had a fairly long muzzle, and a nearly absent nasal bone, comparable to Asian

snub-nosed monkeys __NOTOC__ Snub-nosed monkeys are a group of Old World monkeys and make up the entirety of the genus ''Rhinopithecus''. The genus is rare and not fully researched. Some taxonomists group snub-nosed monkeys together with the genus ''Pygathrix''. Sn ...

. Compared to its modern relatives, it would have had a noticeably short nose. However, postcranial elements are nearly indistinguishable from the corresponding bones of living colobus monkeys outside of size, which suggests that it was a mostly arboreal, folivorous species in spite of its greater size.

References

Colobinae Pliocene primates Pleistocene primates Pliocene mammals of Africa Pleistocene mammals of Africa Prehistoric primate genera {{Paleo-primate-stub