''Heteromeryx'' is an extinct

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

artiodactyl The even-toed ungulates (Artiodactyla , ) are ungulates—hoofed animals—which bear weight equally on two (an even number) of their five toes: the third and fourth. The other three toes are either present, absent, vestigial, or pointing poster ...

, of the family

Protoceratidae Protoceratidae is an extinct family of herbivorous North American artiodactyls (even-toed ungulates) that lived during the Eocene through Pliocene at around 46.2—4.9 Mya, existing for about 41 million years. Classification Protoceratidae was ...

, endemic to North America. They lived during the Late

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

37.2—33.9 Ma, existing for approximately . They resembled

deer Deer or true deer are hoofed ruminant mammals forming the family Cervidae. The two main groups of deer are the Cervinae, including the muntjac, the elk (wapiti), the red deer, and the fallow deer; and the Capreolinae, including the re ...

, 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, ...

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 ind ...

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 2010 United States Census, the population was 1,311. Its county seat is Harrison. Sioux County is included in the Scottsbluff, NE Micropolitan Statistical Area. In the Nebrask ...

*French Creek Site,

Custer County, South Dakota Custer County is a county in the U.S. state of South Dakota. As of the 2020 United States Census, the population was 8,318. Its county seat is Custer. The county was created in 1875, and was organized in 1877. Geography Custer County lies on t ...

References

Protoceratids Priabonian genus extinctions Eocene even-toed ungulates Eocene mammals of North America Fossil taxa described in 1905 Prehistoric even-toed ungulate genera {{paleo-eventoedungulate-stub