Protoceratidae is an extinct family of herbivorous Artiodactyla (even-toed ungulates) that lived during the Eocene through Pliocene. While early members of the group were hornless, in later members males developed elaborate cranial ornamentation. They are variously allied with Ruminant or Tylopoda.
Classification
Protoceratidae was erected by Othniel Charles Marsh in 1891, with the type genus
Protoceras and assigned to the
Artiodactyla.
[O. C. Marsh. 1891. A horned artiodactyle (Protoceras celer) from the Miocene. The American Journal of Science and Arts, series 3 41(241):81-82][S. D. Webb, B. L. Beatty, and G. Poinar, Jr. 2003. New evidence of Miocene Protoceratidae including a new species from Chiapas, Mexico. Bulletin of the American Museum of Natural History 279:348-367][D. R. Prothero and J. A. Ludtke. 2007. Family Protoceratidae. in D. R. Prothero and S. Foss (eds.), The Evolution of Artiodactyls 169-176] It was later assigned to
Pecora,
[H. J. Cook. 1934. New artiodactyls from the Oligocene and Lower Miocene of Nebraska. American Midland Naturalist 15(2):148-165] and more recently to
Ruminantia[Thurmond and Jones (1981) ] or
Tylopoda.
[Carroll and by Webb et al., 2003 ] However, recently a relationship to
in the infraorder
Tragulina has been proposed.
Morphology
When alive, protoceratids would have resembled
deer, though they were not directly related. Protoceratids ranged from 1 to 2 m in length, from about the size of a
roe deer to an
Wapiti. Unlike many modern ungulates, they lacked
in their legs. Their dentition was similar to that of modern deer and cattle, suggesting they fed on tough grasses and similar foods, with a complex stomach similar to that of
. At least some forms are believed to have lived in
.
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 noses. 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 of a giraffe. The females were either hornless, or had far smaller horns than the males. Horns 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 of some modern deer.
Genera by epoch
Eocene
Oligocene
Miocene
Pliocene
