Oligocene Artiodactyla

Entelodon (meaning 'complete teeth', from Ancient Greek entelēs 'complete' and odōn 'tooth', referring to its "complete" eutherian dentition), formerly called Elotherium, is an extinct genus of entelodont artiodactyl found in Eurasia. Fossils of species of Entelodon are found in Paleogene strata ranging in age from the Houldjinian (37.2–33.9 mya) until the Rupelian epoch of the early Oligocene (33.9–28.4 mya).

Archaeotherium (, meaning "ancient beast") is an extinct genus of entelodont artiodactyl endemic to North America during the Eocene and Oligocene epochs (35–28 mya). Archaeotherium fossils are most common in the White River Formation of the Great Plains, but they have also been found in the John Day Basin of Oregon and the Trans-Pecos area of Texas. Archaeotherium's fossils come from North America, between the Priabonian and Rupelian stages of the Eocene and Oligocene (35–28 million years ago). Up to fifteen species of Archaeotherium have been identified, which are divided into three subgenera

thumb|Daeodon shoshonensis life restoration thumb|Daeodon (Dinohyus) hollandi, complete skeleton from the Agate Fossil Beds National Monument|Agate Springs Fossil Quarry in Nebraska. See text for nomenclature history

Anthracotherium (from Ancient Greek ἄνθραξ (ánthrax), meaning "coal", and θηρίον (theríon), meaning "beast") is an extinct genus of anthracotheriid artiodactyls characterized by having 44 teeth, with five semi-crescentic cusps on the crowns of the upper molars. The genus ranged from the middle Eocene period until the early Miocene, having a distribution throughout Eurasia probably even reaching South East Asia (Kalimantan and West Timor). Material subjectively assigned to Anthracotherium from Pakistan suggests the last species died out soon after the start of the Miocene.

Merycoidodon ("ruminating teeth") is an extinct genus of herbivorous artiodactyl of the family Merycoidodontidae, more popularly known by the name Oreodon ("hillock teeth"). It was endemic to North America during the Middle Eocene to Middle Miocene (46—16 mya) existing for approximately .

Poebrotherium ( ) is an extinct genus of camelid, endemic to North America. They lived from the Eocene to Miocene epochs, 46.3—13.6 mya, existing for approximately .

Elomeryx is an extinct genus of artiodactyl ungulate, and is among the earliest known anthracotheres. The genus was extremely widespread, first being found in Asia in the middle Eocene, in Europe during the latest Eocene, and having spread to North America by the early Oligocene. The closest living relatives of the Elomeryx are said suids, and hippopotamids (hippopotami and cetaceans). thumb|left|Restoration of E. armatus Elomeryx was about in body length, and had a long, vaguely horse-like head. It had small tusks which it used to uproot plants, and spoon-shaped incisors ideal for pulling an

Protoceras ('first horn') is an extinct genus of Artiodactyla, of the family Protoceratidae, endemic to North America. It lived from the Oligocene to the Early Miocene 33.3—16.0 Ma, existing for approximately .

Oxydactylus is an extinct genus of camelid endemic to North America. It lived from the Late Oligocene to the Middle Miocene (28.4–13.7 mya), existing for approximately . The name is from the Ancient Greek οξύς (oxys, "sharp")and δάκτυλος (daktylos, "finger").

left|thumb|234x234px|Lithograph from 1896

Dichobunidae is an extinct family of basal artiodactyl mammals from the early Eocene to late Oligocene of North America, Europe, and Asia. The Dichobunidae include some of the earliest known artiodactyls, such as Diacodexis.

Hypertragulidae is an extinct family of Paleogene ruminants endemic to North America from the Eocene until the Oligocene.

Merycochoerus (Greek: "ruminant" (merux)-like "swine" (khoiros)) is an extinct genus of oreodont of the family Merycoidodontidae, endemic to North America. They lived during the Early Oligocene 33.9—30.8 mya, existing for approximately . Fossils are widespread through the western United States.

Paraentelodon is an extinct entelodont from the Late Oligocene of Asia. The fossils of the type species P. intermedium were found in Georgia, Kazakhstan and China. An indeterminate species represents in Bugti Hills which is the late Oligocene of Pakistan.

Leptomeryx is an extinct genus of artiodactyl that lived in North America during the middle Eocene through early Miocene. One of the earliest ruminants, it belongs to the extinct family Leptomerycidae, which is related to today's chevrotains. Most fossils were found in the badlands of the Midwestern United States in sedimentary rocks of the White River Group, in the Brule and Chadron formations. Additional remains have been reported from southern Canada and Mexico. The genus was scientifically described in 1853 by Joseph Leidy and includes several species.

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 Early Miocene (33.9—16.3 mya) and lived for approximately .

Hyotherium (meaning "pig beast", due to its resemblance to modern day pigs.) was an extinct genus of even-toed ungulates under the Hyotheriinae group (a group that also consists of Chicochoerus, Xenohyus and more) of the Suidae family. It existed during the Miocene in Europe and Perim Island, India. It was named by Von Mayer in 1834.

Bothriogenys is a genus of anthracotheres that lived in Eastern Africa during the Late Eocene to Early Oligocene.

Sespia ("of Sespe Creek") is an extinct genus of oreodont endemic to North America. They lived during the Late Oligocene 26.3—24.8 mya, existing for approximately . Sespia was cat to goat-sized and desert-dwelling. The genus was closely related to the larger Leptauchenia.

extinct family of mammals

Eporeodon is an extinct genus of oreodont belonging to the family Merycoidontidae. It lived from the Oligocene epoch 30.8—24.8 mya) existing for approximately .

Agriochoerus is an extinct genus of scansorial herbivore of the tylopod family Agriochoeridae, endemic to North America. Agriochoerus and other agriochoerids possessed claws, which is rare within Artiodactyla, as well as likely being scansorial. Agriochoerus was first described in 1869.

Amphirhagatherium is an extinct genus of artiodactyl that lived in Northern Europe during the late Eocene to Early Oligocene.

Paratylopus is an extinct genus of camelid, endemic to North America. It lived from the Oligocene to the Middle Miocene 33.9—16.0 Mya, existing for approximately . Fossils have been found in western Wyoming, and from eastern Nebraska to northeastern Colorado and southwestern South Dakota.