Leptoreodon
Encyclopedia
Leptoreodon is a small extinct genus
of Artiodactyla, of the family Protoceratidae
, endemic to North America
from the Eocene
epoch (Uintan
to Duchesnean
stage) 40.2—33.9 Ma, existing for approximately .
by Peterson (1919); and to Protoceratidae
by Wortman (1898), Carroll (1988), Prothero (1998) and Prothero and Ludtke (2007).
. However they were more closely related to camelids
. In addition to having horns in the more usual place, protoceratids had additional, rostral horns above the orbital cavity
.
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 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 (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...
to Duchesnean
Duchesnean
The Duchesnean North American Stage on the geologic timescale is a North American Land Mammal Age , with an age from 42 to 38 million years BP, representing . It falls within the Eocene epoch. The Duchesnean is preceded by the Uintan and followed by the Chadronian NALMA.The Duchesnean falls within...
stage) 40.2—33.9 Ma, existing for approximately .
Taxonomy
Leptoreodon was named by Wortman (1898). It was assigned to HypertragulidaeHypertragulidae
Hypertragulidae is an extinct family of even-toed ungulates , endemic to North America, Europe, and Asia during the Eocene through Miocene, living 46.2—13.6 Ma, existing for approximately ....
by Peterson (1919); and to 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:...
by Wortman (1898), Carroll (1988), Prothero (1998) and Prothero and Ludtke (2007).
Morphology
Leptoreodon resembled deerDeer
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...
.
Body mass
Four fossil specimens of Prosynthetoceras were measured by M. Mendoza, C. M. Janis, and P. Palmqvist for body mass.- Specimen 1: 12.5 kg (27.6 lb)
- Specimen 2: 10.3 kg (22.7 lb)
- Specimen 3: 9.5 kg (20.9 lb)
- Specimen 3: 10.6 kg (23.4 lb)
Fossil distribution
Fossils have been recovered from:- Devil's Graveyard Formation, Brewster County, TexasBrewster County, TexasBrewster County is a county located in western part of the US state of Texas, along the border with Mexico. It is one of the nine counties that comprise the Trans-Pecos region of West Texas. As of the 2000 census, the population is 8,866. In 2009, the population was estimated to be 9,481. Its...
- Webb County, TexasWebb County, TexasWebb 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...
- Swift Current Creek, Cypress Hills FormationCypress Hills FormationThe Cypress Hills Formation is a stratigraphical unit of Oligocene age in the Western Canadian Sedimentary Basin.It takes the name from the Cypress Hills, and was first described in outcrops on the slopes of the Cypress Hills by M.Y. Williams and W.S. Dyer in 1930...
, SaskatchewanSaskatchewanSaskatchewan is a prairie province in Canada, which has an area of . Saskatchewan is bordered on the west by Alberta, on the north by the Northwest Territories, on the east by Manitoba, and on the south by the U.S. states of Montana and North Dakota....