''Cormohipparion'' (Greek: "noble" (cormo), "pony" (hipparion) is an extinct genus of horse belonging to the

tribe The term tribe is used in many different contexts to refer to a category of human social group. The predominant worldwide use of the term in English is in the discipline of anthropology. The definition is contested, in part due to conflict ...

Hipparionini Hipparionini is a tribe of three-toed horses in the subfamily Equinae. They had body forms similar to modern equines, with high-crowned teeth. They first appeared in North America during the Early Miocene around 17 million years ago, before migrat ...

that lived in North America and Eurasia during the late Miocene to Pliocene (

Hemphillian The Hemphillian North American Stage on the geologic timescale is a North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), typically set from 10,300,000 to 4,900,000 years BP. It is usually considered t ...

Blancan The Blancan North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), typically set from 4,750,000 to 1,806,000 years BP, a period of .NALMA classification). They grew up to long.

Taxonomy

The genus ''Cormohipparion'' was coined for the extinct hipparionin horse ''"Equus" occidentale'', described by

Joseph Leidy Joseph Mellick Leidy (September 9, 1823 – April 30, 1891) was an American paleontologist, parasitologist and anatomist. Leidy was professor of anatomy at the University of Pennsylvania, later becoming a professor of natural history at Swarth ...

in 1856. However it was soon argued that the partial material fell within the range of morphological variation seen in ''

Hipparion ''Hipparion'' is an extinct genus of three-toed, medium-sized equine belonging to the extinct tribe Hipparionini, which lived about 10-5 million years ago. While the genus formerly included most hipparionines, the genus is now more narrowly defi ...

'', and that the members of ''Cormohipparion'' belonged instead within ''Hipparion''. This rested on claims that pre-orbital morphology did not have any taxonomic significance, a claim that detailed study of quarry sections later showed to be false. The genus was originally identified by a closed off preorbital fossa, but later examinations of the cheek teeth, specifically the lower

cheek teeth Cheek teeth or postcanines comprise the molar and premolar teeth in mammals. Cheek teeth are multicuspidate (having many folds or tubercles). Mammals have multicuspidate molars (three in placentals, four in marsupials, in each jaw quadrant) and ...

, of ''Cormohipparion'' specimens found that they were indeed valid and distinct from ''Hipparion''. A reappraisal of many horse genera was thus conducted in 1984, and the proposed synonymy was not acknowledged by later literature. ''C. ingenuum'' holds the distinction for being the first prehistoric horse to be described in Florida, as well as being one of the most common species of extinct three-toed horses found to be in Florida, lasting until the early Pliocene. ''Cormohipparion'' ''emsliei'' has the distinction of being the last hipparion horse known from the fossil record. The genus is considered to represent an ancestor to ''

Hippotherium ''Hippotherium'' is an Extinction, extinct genus of Equidae, horse that lived during the Miocene through Pliocene ~13.65—6.7 Mya (unit), Mya, existing for . The last known surviving ''Hippotherium'' was ''H. malpassii'', found in Italy. Spe ...

''. Its fossils have been recovered from as far south as Mexico. Fossils have been found in the Great Plains and Rio Grande regions of North America, Mexico, Florida, and Texas, which shows that they were herding animals. Fossils have been unearthed in

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

Louisiana Louisiana ( ; ; ) is a state in the Deep South and South Central regions of the United States. It borders Texas to the west, Arkansas to the north, and Mississippi to the east. Of the 50 U.S. states, it ranks 31st in area and 25 ...

Nebraska Nebraska ( ) is a landlocked U.S. state, state in the Midwestern United States, Midwestern region of the United States. It borders South Dakota to the north; Iowa to the east and Missouri to the southeast, both across the Missouri River; Ka ...

South Dakota South Dakota (; Sioux language, Sioux: , ) is a U.S. state, state in the West North Central states, North Central region of the United States. It is also part of the Great Plains. South Dakota is named after the Dakota people, Dakota Sioux ...

Honduras Honduras, officially the Republic of Honduras, is a country in Central America. It is bordered to the west by Guatemala, to the southwest by El Salvador, to the southeast by Nicaragua, to the south by the Pacific Ocean at the Gulf of Fonseca, ...

Costa Rica Costa Rica, officially the Republic of Costa Rica, is a country in Central America. It borders Nicaragua to the north, the Caribbean Sea to the northeast, Panama to the southeast, and the Pacific Ocean to the southwest, as well as Maritime bo ...

, and

Panama Panama, officially the Republic of Panama, is a country in Latin America at the southern end of Central America, bordering South America. It is bordered by Costa Rica to the west, Colombia to the southeast, the Caribbean Sea to the north, and ...

. Fossils have also been found in

India India, officially the Republic of India, is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area; the List of countries by population (United Nations), most populous country since ...

and

Turkey Turkey, officially the Republic of Türkiye, is a country mainly located in Anatolia in West Asia, with a relatively small part called East Thrace in Southeast Europe. It borders the Black Sea to the north; Georgia (country), Georgia, Armen ...

Evolution

Ashfall Fossil Beds - Teleoceras and Cormohipparion

A species of ''Cormohipparion'' closely related to ''C. occidentale'' is thought to have crossed the Bering land Bridge over into Eurasia around 11.4-11 million years ago, becoming the ancestor to Old World hipparionines.

References

{{Authority control Miocene horses Pliocene horses Zanclean genera Messinian genera Tortonian genera Langhian genera Serravallian genera Miocene mammals of North America Pliocene mammals of North America Hemphillian Blancan Neogene Honduras Neogene Mexico Neogene Panama Neogene United States Fossils of Honduras Fossils of Mexico Fossils of Panama Fossils of the United States Fossil taxa described in 1977 Hipparionini