Toromeryx is a medium-sized extinct genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of Artiodactyla, of the family Protoceratidae

Protoceratidae

Protoceratidae is an extinct family of herbivorous North American artiodactyls that lived during the Eocene through Pliocene at around 46.2—4.9 Ma., existing for approximately .-Taxonomy:...

, endemic to southwestern North America

North America

North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

 from the Eocene

Eocene

The Eocene Epoch, lasting from about 56 to 34 million years ago , is a major division of the geologic timescale and the second epoch of the Paleogene Period in the Cenozoic Era. The Eocene spans the time from the end of the Palaeocene Epoch to the beginning of the Oligocene Epoch. The start of the...

 epoch (Late Uintan

Uintan

The Uintan North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology , typically set from 46,200,000 to 42,000,000 years BP lasting . It is usually considered to fall within the Eocene epoch...

 stage) 46.2—42 Ma, existing for approximately .

Taxonomy

Toromeryx was named by Wilson (1974). Its type is Toromeryx marginensis. It was assigned to Protoceratidae by Wilson (1974), Carroll (1988), Prothero (1998) and Prothero and Ludtke (2007).

Morphology

Toromeryx resembled deer

Deer

Deer are the ruminant mammals forming the family Cervidae. Species in the Cervidae family include white-tailed deer, elk, moose, red deer, reindeer, fallow deer, roe deer and chital. Male deer of all species and female reindeer grow and shed new antlers each year...

. However they were more closely related to camelids

Camel

A camel is an even-toed ungulate within the genus Camelus, bearing distinctive fatty deposits known as humps on its back. There are two species of camels: the dromedary or Arabian camel has a single hump, and the bactrian has two humps. Dromedaries are native to the dry desert areas of West Asia,...

. In addition to having horns in the more usual place, protoceratids had additional, rostral horns above the orbital cavity

Orbit (anatomy)

In anatomy, the orbit is the cavity or socket of the skull in which the eye and its appendages are situated. "Orbit" can refer to the bony socket, or it can also be used to imply the contents...

. Poabromylus was smaller than Miocene members of Tylopoda: Paratoceras

Paratoceras

Paratoceras is a medium-sized extinct genus of Artiodactyla, of the family Protoceratidae, endemic to North America from the Miocene epoch, 16.3—15.97 Ma, existing for approximately .-Taxonomy:...

, Protoceras

Protoceras

Protoceras is an extinct genus of Artiodactyla, of the family Protoceratidae, endemic to North America from the Oligocene through Miocene 33.9—20.6 Ma, existing for approximately .-Taxonomy:...

, and Pseudoprotoceras

Pseudoprotoceras

Pseudoprotoceras is an extinct genus of Artiodactyla, of the family Protoceratidae, endemic to central North America from the Eocene epoch 42—39.9 Ma, existing for approximately .-Taxonomy:...

.

Fossil distribution

Fossils have been recovered from:

• Candelaria TMM 31281 Colmena Tuff Formation, Presidio County, Texas
  Presidio County, Texas
  Presidio County is a county located in the U.S. state of Texas. In 2000, its population was 7,304. Its county seat is Marfa. Presidio County is in the Trans-Pecos region of West Texas and is named for the ancient border settlement of Presidio del Norte.-Geography:Presidio County is triangular in...
  
  
• Casa Blanca Site, Laredo Formation, Webb County, Texas
  Webb County, Texas
  Webb County is a county located in the U.S. state of Texas. The official 2010 population for the county is 250,304. In 2000, its population was 193,117, and in 2006 its population had been estimated to have reached to 231,470. Its county seat is Laredo...