''Protoceras'' ('first horns') is an extinct

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

Artiodactyla 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 North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

. It lived from the

Oligocene The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but the ...

to the Early

Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recen ...

33.3—16.0 Ma, existing for approximately .''Protoceras'' at fossilworks
/ref>

Morphology

''Protoceras'' was long and resembled a

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 reindeer ...

in terms of body shape. Like some other protoceratids it had three pairs of blunt

horn Horn most often refers to: *Horn (acoustic), a conical or bell shaped aperture used to guide sound ** Horn (instrument), collective name for tube-shaped wind musical instruments *Horn (anatomy), a pointed, bony projection on the head of various ...

s on its skull. In life these were probably covered with skin, much like the

ossicone Ossicones are columnar or conical skin-covered bone structures on the heads of giraffes, male okapi, and some of their extinct relatives. Ossicones are distinguished from the superficially similar structures of horns and antlers by their unique ...

s of a

giraffe The giraffe is a large African hoofed mammal belonging to the genus ''Giraffa''. It is the tallest living terrestrial animal and the largest ruminant on Earth. Traditionally, giraffes were thought to be one species, ''Giraffa camelopardalis ...

. ''Protoceras'' was

sexually dimorphic Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most ani ...

: females only had one pair of horns, on the back of the skull, which was shorter than the same pair in males. Males probably used these horns for display, impressing females, or intimidating rivals. Due to the orientation of the horns the males probably displayed them sideways instead of frontally. ''Protoceras'' was one of the earliest and most primitive protoceratids, still possessing upper

incisor Incisors (from Latin ''incidere'', "to cut") are the front teeth present in most mammals. They are located in the premaxilla above and on the mandible below. Humans have a total of eight (two on each side, top and bottom). Opossums have 18, whe ...

s and four functional toes (later genera had only two functional, hooved toes). It lived in the deserts of the Late Oligocene, alongside the oreodont ''

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. The genus was endemic to North America during the Late Oligocene to Earl ...

''.

References

{{Taxonbar, from=Q1819072 Protoceratids Oligocene even-toed ungulates Miocene even-toed ungulates Oligocene mammals of North America Miocene mammals of North America Aquitanian genus extinctions White River Fauna Rupelian genus first appearances Taxa named by Othniel Charles Marsh Fossil taxa described in 1891 Prehistoric even-toed ungulate genera