Protopithecus

Protopithecus is an extinct genus of large New World monkey that lived during the Pleistocene. Fossils have been found in the Toca da Boa Vista cave of Brazil, as well as other locales in the country.[1] Fossils of another, less robust, large ateline monkey, Caipora, were also discovered in Toca da Boa Vista.[2]

Protopithecus Temporal range: Late Pleistocene (Ensenadan-Lujanian) ~0.126–0.012 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Primates
Suborder:	Haplorhini
Infraorder:	Simiiformes
Family:	Atelidae
Subfamily:	Atelinae
Genus:	†Protopithecus Lund 1838
Species
P. bonariensis P. brasiliensis

Description and paleobiology

At an estimated weight of 22.6 kilograms (50 lb), it was the largest New World monkey known to exist. With slightly longer arms than legs, Protopithecus resembled spider monkeys, but its limb bones were nearly twice as thick. Its head was more similar to a howler monkey's, which has a lower jaw that juts forward to accommodate an apple-size vocal sac. As such, Protopithecus may have been able to howl just like them.[3]

Although its large size has led to the suggestion that it may have been partially or primarily terrestrial, Halenar (2011) found no adaptations to terrestrial locomotion in the skeleton of Protopithecus, which has a morphology characteristic of arboreal monkeys, although given its estimated weight, it is unlikely to have been a suspensory feeder like Ateles and Brachyteles. It may have been an arboreal quadruped which made occasional use of the ground, comparable to a great ape or the larger subfossil lemurs.[4]

Although closely related, howler and spider monkeys split from their common ancestor long before Protopithecus evolved. This means that the distinctive features of these modern monkeys have evolved more than once.

Paleoecology

Other animals found in Toca da Boa Vista include another large atelid, Caipora bambuiorum, as well as Arctotherium brasiliensis, Catonyx cuvieri, Desmodus draculae, Nothrotherium maquinense, Protocyon troglodytes, Smilodon populator, giant anteaters, collared peccaries, crab-eating foxes and raccoons, striped hog-nosed skunks, and guanacoes.[2]

The environment inhabited by Protopithecus is unclear. Most of Brazil was thought to have been covered in open tropical cerrado vegetation during the Late Pleistocene, but if Protopithecus and Caipora were arboreal, their presence suggests that the region may have supported a dense closed forest during the Late Pleistocene.[2][5] It is possible that the region alternated between dry open savannah and closed wet forest throughout the climate change of the Late Pleistocene.[4]

References

1. Halenar-Price, Lauren (2012). "Paleobiology of Protopithecus brasiliensis, a Plus-Size Pleistocene Platyrrhine from Brazil" (dissertation) – via www.academia.edu. Cite journal requires |journal= (help)
2. Cartelle, Castor; Hartwig, W. C. (1996). "A new extinct primate among the Pleistocene megafauna of Bahia, Brazil". Proceedings of the National Academy of Sciences. 93 (13): 6405–6409.
3. "Mega-monkey". Discover Magazine. 1 Sep 1996.
4. Halenar, Lauren B. (December 2011). "Reconstructing the Locomotor Repertoire of Protopithecus brasiliensis". The Anatomical Record. 294 (12): 2048–2063.
5. Eisenberg, John F.; Redford, Kent H. (1989). Mammals of the Neotropics, Volume 3: Ecuador, Bolivia, Brazil. University of Chicago Press. p. 247. ISBN 9780226195421.