''Pascualihippus'' is an

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

notoungulate Notoungulata is an extinct order of ungulates that inhabited South America from the early Paleocene to the end of the Pleistocene, living from approximately 61 million to 11,000 years ago. Notoungulates were morphologically diverse, with forms re ...

belonging to the family

Notohippidae Notohippidae is a paraphyly, paraphyletic extinct Family (biology), family of Notoungulata, notoungulate mammals from South America. Notohippids are known from the Eocene and Oligocene Epoch (reference date), epochs.McKenna, Malcolm C., and Bell ...

. It lived during the Late

Oligocene The Oligocene ( ) is a geologic epoch (geology), epoch of the Paleogene Geologic time scale, Period that extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that defin ...

, in what is now

Bolivia Bolivia, officially the Plurinational State of Bolivia, is a landlocked country located in central South America. The country features diverse geography, including vast Amazonian plains, tropical lowlands, mountains, the Gran Chaco Province, w ...

Description

This genus is primarily known from a skull and a few postcranial bones, and it likely was about the size of a sheep. ''Pascualihippus'' had a high skull, with a broad, blunt muzzle, with the two first incisors forming a transverse line across the anterior part of the premaxilla, followed by a narrowing of the muzzle when viewed from above. These characteristics are somewhat similar to those found in

Toxodontidae Toxodontidae is an extinct family of notoungulate mammals, known from the Oligocene to the Holocene (11,000 BP) of South America, with one genus, '' Mixotoxodon'', also known from the Pleistocene of Central America and southern North America (a ...

, such as ''

Adinotherium ''Adinotherium'' (meaning "not terrible beast")Palmer (1904) p. 80. is an extinct genus of toxodontid, large bodied hoofed ungulates which inhabited South America during the Middle to Late Miocene, from 17.5 to 6.8 Ma and existed for approxim ...

'' and ''

Nesodon ''Nesodon'' ("island tooth")Palmer (1904) p. 457. is a genus of Miocene mammal belonging to the extinct order Notoungulata which inhabited southern South America during the Late Oligocene to Miocene living from 29.0 to 16.3 Ma and existed for a ...

''. However, its incisors had roots and the cheek teeth were quite different from those of "true" toxodonts. The molars of ''Pascualihippus'' lacked the typical bifurcation on the central loop. The premaxillary dental arch was linear, indicating that it likely was a grass bruiser. Unlike its relative ''

Eomorphippus ''Eomorphippus'' is an extinct genus of notohippid notoungulate that lived from the Late Eocene to the Early Oligocene in what is today South America. Description This animal was approximately the size of a goat, with a build probably more rob ...

'', its incisors were not protruding.

Classification

''Pascualihippus'' was first described in 1997, based on fossilized remains found in the

Salla Formation Salla, known as Kuolajärvi until 1936, is a municipality of Finland, located in Lapland. The municipality has a population of () and covers an area of of which is water. The population density is . The nearby settlement of Sallatunturi is ...

, in terrains dated from the Late

. ''Pascualihippus'' was originally placed within the family

, a family of toxodont notoungulates with horse-like teeth, with very high-crowned molars. More recent research, however, tends to indicate that this group was paraphyletic, containing increasingly derived forms, some of them close to the ancestors of "true"

. ''Pascualihippus'' seems to have been close to those forms, and is in more modern studies nested at the basis of a clade including its relative '' Argyrohippus'' and more derived

References and Bibliography

*B. J. Shockey. 1997. Two new notoungulates (Family Notohippidae) from the Salla Beds of Bolivia (Deseadan: Late Oligocene): systematics and functional morphology. Journal of Vertebrate Paleontology 17(3):584-599 {{Taxonbar, from=Q97371607 Toxodonts Oligocene mammals of South America Paleogene Bolivia Fossils of Bolivia Fossil taxa described in 1997 Prehistoric placental genera