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.

Protoceratidae was erected by Othniel Charles Marsh in 1891, with the type genus Protoceras and assigned to the Artiodactyla. It was later assigned to Pecora, and more recently to Ruminantia or Tylopoda. Within the Artiodactyla, protoceratids are usually considered to be related to giraffids. However, recently a relationship to chevrotains in the infraorder Tragulina has been proposed.