''Pliopapio'' is an extinct genus of

Old World monkey Old World monkey is the common English name for a family of primates known taxonomically as the Cercopithecidae (). Twenty-four genera and 138 species are recognized, making it the largest primate family. Old World monkey genera include baboons ...

known from the latest part of the

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

to the early Pliocene Epochs from the

Afar Region The Afar Region (; aa, Qafar Rakaakayak; am, አፋር ክልል), formerly known as Region 2, is a regional state in northeastern Ethiopia and the homeland of the Afar people. Its capital is the planned city of Semera, which lies on the pave ...

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 was first described based on a very large series of fossils from the site of Aramis in the

Middle Awash The Middle Awash is a paleoanthropological research area in the Afar Region along the Awash River in Ethiopia's Afar Depression. It is a unique natural laboratory for the study of human origins and evolution and a number of fossils of the earliest ...

, which has been dated by ⁴⁰Ar/³⁹Ar to 4.4 million years old. It has since been found from similarly aged sediments at Gona, approximately 75 km to the North. Additional fossils from the Middle Awash extend its known time range back to at least 5.3 million years ago. There is only one known species, ''Pliopapio alemui''.

Description

In most ways, ''Pliopapio'' is similar other generalized members of the tribe

Papionini Papionini is a tribe of Old World monkeys that includes several large monkey species, which include the macaques of North Africa and Asia, as well as the baboons, geladas, mangabeys, kipunji, drills, and mandrills, which are essentially from sub- ...

, such as the living macaques,

mangabey Mangabeys are West-African Old World monkeys, with species in three of the six genera of tribe Papionini. The more typical representatives of ''Cercocebus'', also known as the white-eyelid mangabeys, are characterized by their bare, upper eye-l ...

s, and

baboon Baboons are primates comprising the genus ''Papio'', one of the 23 genera of Old World monkeys. There are six species of baboon: the hamadryas baboon, the Guinea baboon, the olive baboon, the yellow baboon, the Kinda baboon and the chacma ...

s. In overall size, ''P. alemui'' was close to the larger macaques and smaller baboons. Based on dental measurements, females are estimated to have averaged 8.5 Kg in body weight and males approximately 12 Kg. This suggests only a modest level of sexual dimorphism in body size. ''Pliopapio'' possessed a relatively elongate and narrow muzzle and a brain case that lacked superstructures such as

sagittal The sagittal plane (; also known as the longitudinal plane) is an anatomical plane that divides the body into right and left sections. It is perpendicular to the transverse and coronal planes. The plane may be in the center of the body and divi ...

or nuchal crests. Dentally, it is similar to most papionin monkeys, but the molar teeth are somewhat narrower and taller. A few limb fragments have been tentatively allocated to P. alemui. They suggest it was a semi-terrestrial quadrupedal monkey that was more adapted to arboreal locomotion than

s, but less than crested mangabeys.

Diet

The dentition suggests it had an opportunistic and omnivorous diet similar to many living papionin monkeys. Analysis of the chewing surfaces of the molar teeth found microwear consistent with a diet of fruits and or leaves, and of softer food items in particular. Carbon isotopes from tooth enamel reflect incorporation of more savanna-based foods (i.e. C4/CAM ) than ''Kuseracolobus aramisi'' a colobine monkey, but fewer than the human ancestor ''Ardipithecus ramidus'' at Aramis. Carbon isotopic analysis of ''P. alemui'' tooth enamel from Gona showed similar results. From Aramis, analysis of oxygen isotopes may suggest more fruit than leaves, whereas at Gona, enamel oxygen isotopes suggest more access to open water.

References

{{Taxonbar, from=Q65080465 Papionini Prehistoric primate genera Prehistoric monkeys