Merycochoerus 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 terrestrial

Terrestrial animal

Terrestrial animals are animals that live predominantly or entirely on land , as compared with aquatic animals, which live predominantly or entirely in the water , or amphibians, which rely on a combination of aquatic and terrestrial habitats...

 herbivore

Herbivore

Herbivores are organisms that are anatomically and physiologically adapted to eat plant-based foods. Herbivory is a form of consumption in which an organism principally eats autotrophs such as plants, algae and photosynthesizing bacteria. More generally, organisms that feed on autotrophs in...

 of the family

Family (biology)

In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 Merycoidodontidae (oreodont

Oreodont

Oreodons, sometimes called prehistoric "ruminating hogs," were a family of cud-chewing plant-eater with a short face and tusk-like canine teeth...

), 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...

 during the Late Oligocene to Early Miocene

Early Miocene

The Early Miocene is a sub-epoch of the Miocene Epoch made up of two stages: the Aquitanian and Burdigalian stages....

 (28.4—16.3 mya) existing for approximately .

Merycochoerus was a cud-chewing

Cud

Cud is a portion of food that returns from a ruminant's stomach in the mouth to be chewed for the second time. More accurately, it is a bolus of semi-degraded food regurgitated from the reticulorumen of a ruminant. Cud is produced during the physical digestive process of rumination, or "chewing the...

 plant-eater

Herbivore

Herbivores are organisms that are anatomically and physiologically adapted to eat plant-based foods. Herbivory is a form of consumption in which an organism principally eats autotrophs such as plants, algae and photosynthesizing bacteria. More generally, organisms that feed on autotrophs in...

 with a short face, tusk-like canine teeth, heavy body, long tail, short feet, and four-toed

Even-toed ungulate

The even-toed ungulates are ungulates whose weight is borne about equally by the third and fourth toes, rather than mostly or entirely by the third as in odd-toed ungulates such as horses....

 hoove

Hoof

A hoof , plural hooves or hoofs , is the tip of a toe of an ungulate mammal, strengthened by a thick horny covering. The hoof consists of a hard or rubbery sole, and a hard wall formed by a thick nail rolled around the tip of the toe. The weight of the animal is normally borne by both the sole...

s.. The 1 metres (3.3 ft) long animals are thought to have been amphibious, as members of the genus possessed an elongated, barrel-shaped 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...

 and short limbs that are typical adaptations found in semi-aquatic mammals. P. superbus had a long tapir-like face, while P. carrikeri had a short, somewhat pig-like face.

Taxonomy

Merycochoerus was named by Joseph Leidy

Joseph Leidy

Joseph Leidy was an American paleontologist.Leidy was professor of anatomy at the University of Pennsylvania, and later was a professor of natural history at Swarthmore College. His book Extinct Fauna of Dakota and Nebraska contained many species not previously described and many previously...

 in 1858. Cope in 1884 states the genus to be a nomen nudum

Nomen nudum

The phrase nomen nudum is a Latin term, meaning "naked name", used in taxonomy...

 in Leidy 1858 and Leidy 1869, but validated by Leidy 1873; however, Cope then accepts 1858 as the correct date for M. proprius. Its type is Merycochoerus proprius. It was assigned to Merycoidodontidae by Leidy (1858) and Lander (1998). The genera Megoreodon, Paracotylops, Promerycochoerus, and Superdesmatochoerus were synonymized with Merycochoerus as junior synonyms by B. Lander in 1998.

Morphology

A single specimen was examined by M. Mendoza for body mass and estimated to have a weight of 444.3 kg (979.5 lbs).

Species

• M. carrikeri (syn. Promerycochoerus thomsoni)
• M. chelydra (syn. Promerycochoerus barbouri)
• M. magnus
• M. matthewi
• M. pinensis
• M. proprius (type species)
• M. superbus (syn. M. fricki, M. leidyi, M. macrostegus, M. montanus, M. temporalis, Promerycochoerus grandis, P. hatcheri, P. hollandi, P. inflatus, P. latidens, P. loomisi, P. lulli, P. marshi, P. microcephalus)
• M. vantasselensis