''Heteromeryx'' is an extinct

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 ...

artiodactyl Artiodactyls are placental mammals belonging to the order Artiodactyla ( , ). Typically, they are ungulates which bear weight equally on two (an even number) of their five toes (the third and fourth, often in the form of a hoof). The other t ...

, of the family

Protoceratidae Protoceratidae is an extinct family of herbivorous North American artiodactyls (even-toed ungulates) that lived during the Eocene through Pliocene. While early members of the group were hornless, in later members males developed elaborate crani ...

, endemic to

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

. They lived during the Late

Eocene The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes ...

37.2—33.9 Ma, existing for approximately . They resembled

deer A deer (: deer) or true deer is a hoofed ruminant ungulate of the family Cervidae (informally the deer family). Cervidae is divided into subfamilies Cervinae (which includes, among others, muntjac, elk (wapiti), red deer, and fallow deer) ...

, but were more closely related to

camelids Camelids are members of the biological family Camelidae, the only currently living family in the suborder Tylopoda. The seven extant members of this group are: dromedary camels, Bactrian camels, wild Bactrian camels, llamas, alpacas, vicuñas, ...

. Its name comes from hetero (ἕτερος) "different' and meryx "

ruminant Ruminants are herbivorous grazing or browsing artiodactyls belonging to the suborder Ruminantia that are able to acquire nutrients from plant-based food by fermenting it in a specialized stomach prior to digestion, principally through microb ...

Fossil distribution

Fossils have been recovered from: *Big Red Horizon Site,

Presidio County, Texas Presidio County is a county located in the U.S. state of Texas. As of the 2020 census, its population was 6,131. Its county seat is Marfa. The county was created in 1850 and later organized in 1875. Presidio County (K-5 in Texas topological i ...

J. A. Wilson. 1974. Texas Memorial Museum Bulletin 23 *Dirty Creek Ridge Site,

Sioux County, Nebraska Sioux County is a county in the U.S. state of Nebraska. As of the 2020 United States census, the population was 1,135. Its county seat is Harrison. Sioux County is included in the Scottsbluff, NE Micropolitan Statistical Area. In the Nebr ...

*French Creek Site,

Custer County, South Dakota Custer County is a county in the U.S. state of South Dakota. As of the 2020 census, the population was 8,318. Its county seat is Custer. The county was created in 1875, and was organized in 1877. It was named after General George Armstr ...

References

Protoceratids Priabonian genus extinctions Eocene Artiodactyla Eocene mammals of North America Fossil taxa described in 1905 Monotypic prehistoric Artiodactyla genera {{paleo-eventoedungulate-stub