Protoceratidae
Encyclopedia
Protoceratidae is an extinct family of herbivorous North America
n artiodactyls (even-toed ungulates) that lived during the Eocene
through Pliocene
at around 46.2—4.9 Ma., existing for approximately .
. It was assigned to Pecora
by Cook in 1934; to Ruminantia
by Thurmond and Jones (1981) and Spaulding et al. (2009); to Tylopoda
by Carroll and by Webb et al. in 2003. It was assigned to Artiodactyla by Marsh (1891), Hulbert and Whitmore (2006) and Prothero and Ludtke (2007). It was assigned to the infraorder Tragulina
by Spaulding et al., 2009.
, though not directly relating to them. They ranged from 1 to 2 meters in length, from about the size of a Roe Deer
to an Elk
. Unlike many modern ungulates, they lacked a cannon bone in their legs. Their dentition was similar to that of modern deer and cattle, suggesting that they fed on tough grasses and similar foodstuffs, with a complex stomach similar to that of camel
s. It is believed that at least some forms lived in herd
s.
The most dramatic feature of the protoceratids, however, were the horns of the males. In addition to having horns in the more usual place, protoceratids had additional, rostral horns above their nose. These horns were either paired, as in Syndyoceras
, or fused at the base, and branching into two near the tip, as in Synthetoceras
. In life the horns were probably covered with skin, much like the ossicone
s of a giraffe
. The females were either hornless, or had far smaller horns than the males, and were therefore probably used in sexual display or competition for mates. In later forms, the horns were large enough to have been used in sparring between males, much as with the antler
s of some modern deer.
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...
n artiodactyls (even-toed ungulates) that lived during 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...
through Pliocene
Pliocene
The Pliocene Epoch is the period in the geologic timescale that extends from 5.332 million to 2.588 million years before present. It is the second and youngest epoch of the Neogene Period in the Cenozoic Era. The Pliocene follows the Miocene Epoch and is followed by the Pleistocene Epoch...
at around 46.2—4.9 Ma., existing for approximately .
Taxonomy
Protoceratidae was named by Marsh (1891). Its type is ProtocerasProtoceras
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:...
. It was assigned to Pecora
Pecora
The Pecora is a group of hoofed mammals that comprises most of the ruminants, including cattle, sheep, goats, antelopes,deer, giraffes, and pronghorn. The only extant members of the Ruminantia that are not pecorans are the chevrotains, which lack horns and whose four-chambered stomach is less...
by Cook in 1934; to Ruminantia
Ruminantia
Ruminantia includes many of the well-known large grazing or browsing mammals: among them cattle, goats, sheep, deer, and antelope. All members of the Ruminantia are ruminants: they digest food in two steps, chewing and swallowing in the normal way to begin with, and then regurgitating the...
by Thurmond and Jones (1981) and Spaulding et al. (2009); to Tylopoda
Tylopoda
Tylopoda is a suborder of terrestrial herbivorous even-toed ungulates belonging to Artiodactyla. They are extant in the wild in their native ranges of South America and Asia, while Australian feral camels are an introduced species. The group has a long fossil history in North America and Europe...
by Carroll and by Webb et al. in 2003. It was assigned to Artiodactyla by Marsh (1891), Hulbert and Whitmore (2006) and Prothero and Ludtke (2007). It was assigned to the infraorder Tragulina
Tragulina
Tragulina is an infraorder of even-toed ungulates. Only the chevrotains survive to the present, including the genera Tragulus and Hyemoschus.-Taxonomy:The following is the taxonomy of the group...
by Spaulding et al., 2009.
Morphology
Physically, they 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...
, though not directly relating to them. They ranged from 1 to 2 meters in length, from about the size of a Roe Deer
Roe Deer
The European Roe Deer , also known as the Western Roe Deer, chevreuil or just Roe Deer, is a Eurasian species of deer. It is relatively small, reddish and grey-brown, and well-adapted to cold environments. Roe Deer are widespread in Western Europe, from the Mediterranean to Scandinavia, and from...
to an Elk
Wapiti
- Animals :* Elk , from the Cree language waapiti, a large deer species native to western North America and eastern Asia- Places :* Wapiti Pass, a mountain pass in British Columbia, Canada...
. Unlike many modern ungulates, they lacked a cannon bone in their legs. Their dentition was similar to that of modern deer and cattle, suggesting that they fed on tough grasses and similar foodstuffs, with a complex stomach similar to that of camel
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,...
s. It is believed that at least some forms lived in herd
Herd
Herd refers to a social grouping of certain animals of the same species, either wild or domestic, and also to the form of collective animal behavior associated with this or as a verb, to herd, to its control by another species such as humans or dogs.The term herd is generally applied to mammals,...
s.
The most dramatic feature of the protoceratids, however, were the horns of the males. In addition to having horns in the more usual place, protoceratids had additional, rostral horns above their nose. These horns were either paired, as in Syndyoceras
Syndyoceras
Syndyoceras is a small extinct genus of Artiodactyla, of the family Protoceratidae, endemic to central North America from the Eocene epoch 24.8—20.6 Ma, existing for approximately .-Taxonomy:...
, or fused at the base, and branching into two near the tip, as in Synthetoceras
Synthetoceras
Synthetoceras is a large extinct genus of Artiodactyla, of the family Protoceratidae, endemic to North America from the Miocene epoch, 13.6—5.33 Ma, existing for approximately .-Taxonomy:...
. In life the horns were probably covered with skin, much like the ossicone
Ossicone
Ossicones are horn-like protuberances on the heads of giraffes, male okapis, and their extinct relatives, such as Sivatherium, and the climacoceratids, such as Climacoceras. Only giraffids have true ossicones...
s of a giraffe
Giraffe
The giraffe is an African even-toed ungulate mammal, the tallest of all extant land-living animal species, and the largest ruminant...
. The females were either hornless, or had far smaller horns than the males, and were therefore probably used in sexual display or competition for mates. In later forms, the horns were large enough to have been used in sparring between males, much as with the antler
Antler
Antlers are the usually large, branching bony appendages on the heads of most deer species.-Etymology:Antler originally meant the lowest tine, the "brow tine"...
s of some modern deer.
Eocene
- HeteromeryxHeteromeryxHeteromeryx is an extinct genus of Artiodactyla, of the family Protoceratidae, endemic to North America from the Eocene epoch 40.2—33.9 Ma, existing for approximately .-Taxonomy:...
- LeptoreodonLeptoreodonLeptoreodon is a small extinct genus of Artiodactyla, of the family Protoceratidae, endemic to North America from the Eocene epoch 40.2—33.9 Ma, existing for approximately .-Taxonomy:...
- LeptotragulusLeptotragulusLeptotragulus is a small extinct genus of Artiodactyla, of the family Protoceratidae, endemic to North America from the Eocene epoch 40.2—33.9 Ma, existing for approximately .-Taxonomy:...
- PoabromylusPoabromylusPoabromylus is a small extinct genus of Artiodactyla, of the family Protoceratidae, endemic to North America from the Eocene epoch 46.2—33.9 Ma, existing for approximately .-Taxonomy:...
- ToromeryxToromeryxToromeryx is a medium-sized extinct genus of Artiodactyla, of the family Protoceratidae, endemic to southwestern North America from the Eocene epoch 46.2—42 Ma, existing for approximately .-Taxonomy:...
- TrigenicusTrigenicusTrigenicus is a small extinct genus of Artiodactyla, of the family Protoceratidae, endemic to North America from the Late Eocene epoch 37.2—33.9 Ma, existing for approximately .-Taxonomy:...
Miocene
- ParatocerasParatocerasParatoceras 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:...
- ProtocerasProtocerasProtoceras 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:...
- KyptocerasKyptocerasKyptoceras is a small extinct genus of Artiodactyla, of the family Protoceratidae, endemic to southeastern North America from the Miocene to Early Pliocene epoch 23.03—3.6 Ma, existing for approximately .-Taxonomy:...
- LambdocerasLambdocerasLambdoceras is an extinct genus of Protoceratidae belonging to the order Artiodactyla endemic to North America during the Miocene, living epoch 20.6—13.6 Ma, existing for approximately .-Taxonomy:...
- ProsynthetocerasProsynthetocerasProsynthetoceras is an extinct genus of Artiodactyla, of the family Protoceratidae, endemic to North America from the early Miocene epoch 20.6—13.6 Ma, existing for approximately .-Taxonomy:...
- PseudoprotocerasPseudoprotocerasPseudoprotoceras 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:...
- SynthetocerasSynthetocerasSynthetoceras is a large extinct genus of Artiodactyla, of the family Protoceratidae, endemic to North America from the Miocene epoch, 13.6—5.33 Ma, existing for approximately .-Taxonomy:...
- SyndyocerasSyndyocerasSyndyoceras is a small extinct genus of Artiodactyla, of the family Protoceratidae, endemic to central North America from the Eocene epoch 24.8—20.6 Ma, existing for approximately .-Taxonomy:...