Merychyus fossil map
Where fossils of Merychyus have been found, shown on the Earth as it looked about 15 million years ago and on today’s map.
Dots are fossil collections recorded in the Paleobiology Database. The “then” view moves today’s fossil sites back to their positions 15 million years ago (the time slice nearest the median age of the fossils) using the Merdith et al. (2021) plate model; positions are approximate. Open on the timeline map →
| Group | Early mammals |
|---|---|
| Lived | 29.5–5.333 million years ago (Rupelian to Messinian) |
| Periods | Paleogene, Neogene |
| Family | Merycoidodontidae |
| Named by | Leidy 1858 |
| Fossil records | 352 occurrences at 69 locations (PBDB) |
| Found in | United States, Mexico, Canada |
| Rock formations | txn:42488, Runningwater, Marsland, Olcott, John Day, Rosebud |
About Merychyus
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. 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.
Text in “About” is quoted from the Wikipedia article Merychyus (revision 1345022632), licensed under CC BY-SA 4.0; introduction excerpted verbatim, formatting removed. Ages, family, authority and fossil records: Paleobiology Database, accessed 23 October 2026. Ages are those of the rock layers the fossils were found in. Wikidata: Q16985417.
