Protoceras is an 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 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 Oligocene

Oligocene

The Oligocene is a geologic epoch of the Paleogene Period and extends from about 34 million to 23 million years before the present . As with other older geologic periods, the rock beds that define the period are well identified but the exact dates of the start and end of the period are slightly...

 through Miocene

Miocene

The Miocene is a geological epoch of the Neogene Period and extends from about . The Miocene was named by Sir Charles Lyell. Its name comes from the Greek words and and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene. The Miocene follows the Oligocene...

 (Orellan

Orellan

The Orellan 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 33,900,000 to 33,300,000 years BP, a period of . It is usually considered to fall within the Early Oligocene...

 to Harrisonian

Harrisonian

The Harrisonian 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 24,800,000 to 20,600,000 years BP, a period of . It is usually considered to overlap the Chattian and Aquitarian stages...

 stage) 33.9—20.6 Ma, existing for approximately .

Taxonomy

Protoceras was named by Marsh (1891). Its type is Protoceras celer. It is the genus of 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:...

 and subfamily Protoceratinae

Protoceratinae

Protoceratinae is a subfamily of Protoceratidae belonging to the order Artiodactyla endemic to North America living during the Oligocene to Miocene epoch, 33.9—15.97 Ma, existing for approximately .-Taxonomy:...

. It was assigned to Protoceratidae by Marsh (1891) and Carroll (1988); and to Protoceratinae by Matthew (1908), Webb (1981), Prothero (1998), Webb et al. (2003) and Prothero and Ludtke (2007).

Morphology

Protoceras was 1 m (3 ft 4 in) long and resembled a 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...

 in terms of body

Body

With regard to living things, a body is the physical body of an individual. "Body" often is used in connection with appearance, health issues and death...

 shape. Like some other protoceratids it had three pairs of blunt horn

Horn (anatomy)

A horn is a pointed projection of the skin on the head of various animals, consisting of a covering of horn surrounding a core of living bone. True horns are found mainly among the ruminant artiodactyls, in the families Antilocapridae and Bovidae...

s on its skull. In life these 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...

. Protoceras was sexually dimorphic

Sexual dimorphism

Sexual dimorphism is a phenotypic difference between males and females of the same species. Examples of such differences include differences in morphology, ornamentation, and behavior.-Examples:-Ornamentation / coloration:...

 - females only had one pair of horns (the one on the back of the skull), which was shorter than the same pair in males. Males probably used these horns for display, impressing females and/or intimidating rivals. Due to the orientation of the horns the males probably displayed them sideways instead of frontally.

Body mass

Three fossil specimens of Poabromylus were measured by M. Mendoza, C. M. Janis, and P. Palmqvist for body mass. The specimens were determined to weigh:

• Specimen 1: 95.2 kg (209.9 lb)
• Specimen 2: 57.2 kg (126.1 lb)
• Specimen 3: 89.8 kg (198 lb)
• Specimen 4: 54.6 kg (120.4 lb)

Protoceras was one of the earliest and most primitive protoceratids, still possessing upper incisor

Incisor

Incisors are the first kind of tooth in heterodont mammals. They are located in the premaxilla above and mandible below.-Function:...

s and four functional toes (later genera had only two functional, hooved

Claw

A claw is a curved, pointed appendage, found at the end of a toe or finger in most mammals, birds, and some reptiles. However, the word "claw" is also often used in reference to an invertebrate. Somewhat similar fine hooked structures are found in arthropods such as beetles and spiders, at the end...

 toes). Protoceras lived in the deserts of the Late Oligocene, alongside the oreodont Leptauchenia

Leptauchenia

Leptauchenia is an extinct goat-like genus of terrestrial herbivore belonging to the oreodont family Merycoidodontidae, and the type genus of the tribe Leptaucheniini...

.