Merycochoerus fossil map
Where fossils of Merycochoerus 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 | 29.5–11.63 million years ago (Rupelian to Serravallian) |
| Periods | Paleogene, Neogene |
| Family | Merycoidodontidae |
| Named by | Leidy 1858 |
| Fossil records | 74 occurrences at 20 locations (PBDB) |
| Found in | United States, Panama, Canada |
| Rock formations | Runningwater, Marsland, John Day, Troublesome, Rosebud, txn:42488 |
About Merycochoerus
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 3 million years. Fossils are widespread through the western United States.
Merycochoerus was a cud-chewing plant-eater with a long face, tusk-like canine teeth, heavy body, long tail, short feet, and four-toed hooves. The 1 metre (3.3 ft) long animals are thought to have been amphibious, as members of the genus possessed an elongated, barrel-shaped body and short limbs that are typical adaptations found in semi-aquatic mammals.
Text in “About” is quoted from the Wikipedia article Merycochoerus (revision 1369924479), 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: Q6820973.
