Merychyus Temporal range: Miocene (Arikareean-Clarendonian) ~20.4–10.3 Ma PreꞒ Ꞓ O S D C P T J K Pg N
M. elegans fossil, Royal Ontario Museum
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Artiodactyla
Family:	†Merycoidodontidae
Genus:	†Merychyus Leidy 1858
Type species
†Merychyus elegans Leidy 1858
Species
M. arenarum Cope, 1884 M. calaminthus Jahns, 1940 M. elegans Leidy, 1858 (type) M. minimus Peterson, 1907 M. relictus Matthew & Cook, 1909 M. verrucomalus Stevens, 1970
Synonyms
Metoreodon Matthew & Cook, 1909

Merychyus is an extinct genus of oreodont of the family Merycoidodontidae, endemic to North America. It lived during the Miocene, 20.4—10.3 mya, existing for approximately 10 million years.^[1] Fossils are widespread through the central and western United States.

Merychyus was a herbivore with a short face, tusk-like canine teeth, heavy body, long tail, short feet, and four-toed hooves.^{[citation needed]}

Paleoecology

Fossils of Merychyus have been uncovered from Agate Fossil Beds National Monument.^[2] Merychyus was a common prey item for the beardog Daphoenodon, as over half of all herbivore remains uncovered from Daphoenodon burrows at Agate Fossil Beds belonged to Merychyus.^[3]

Fossil distribution

Fossils of the genus have been found in:^[1]

Arikareean

• Chalk Canyon Formation, Arizona
• Diligencia, Sespe & Tick Canyon Formations, California
• Arikaree Formation, North Dakota
• John Day Formation, Oregon
• Delaho Formation, Texas
• Colter, Harrison & Marsland Formations, Wyoming

Harrisonian

• Hector Formation, California
• Agate Springs, Harrison, Marsland & Wildcat Hills Beds Formations, Nebraska
• Rosebud Formation, South Dakota
• Delaho Formation, Texas
• Harrison & Marsland Formations, Wyoming

Other Miocene

• Cypress Hills Formation, Hemingfordian Saskatchewan, Canada
• Suchilquitongo Formation, Mexico
• Barstow, Bopesta, Branch Canyon, Hector, Kramer Beds & Vaqueros Formations, California
• Browns Park & Pawnee Creek Formations, Colorado
• Railroad Canyon Beds Formation, Idaho
• Fleming Formation, Louisiana
• Runningwater, Sheep Creek, Olcott, Loop Fork, Box Butte, Valentine & Ash Hollow Formations, Nebraska
• Truckee & Monarch Mill Formations, Nevada
• Tesuque, Zia Sand & Abiquiu Formations, New Mexico
• Laverne Formation, Oklahoma
• Juntura & John Day Formations, Oregon
• Arikaree & Batesland Formations, South Dakota
• Goliad Formation, Texas
• Marsland, Colter, North Park, Arikaree & Carpenter Ranch Formations, Wyoming