Amynodon fossil map
Where fossils of Amynodon have been found, shown on the Earth as it looked about 45 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 45 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 | 48.07–23.04 million years ago (Lutetian to Chattian) |
| Periods | Paleogene |
| Family | Amynodontidae |
| Named by | Marsh 1877 |
| Fossil records | 134 occurrences at 32 locations (PBDB) |
| Found in | United States, China, Japan |
| Rock formations | Uinta, Tepee Trail, Santiago, Devil's Graveyard, Washakie, Wagon Bed |
About Amynodon
Amynodon ("threatening tooth") is an extinct genus of amynodont that lived in North America during the Middle Eocene, from the late Bridgerian to the late Uintan land mammal age. Several species of Amynodon have been named historically but only the type species, A. advenus, is seen as valid today. Fossils of Amynodon have historically also been reported from Eurasia, though the genus is now generally considered to have been restricted to North America.
Amynodon is the type genus of the family Amynodontidae. It was a medium-sized member of the family, estimated to have weighed 589 kilograms (1,299 lb). Amynodon is the earliest known amynodont in North America, and was probably descended from Asian ancestors that migrated across Beringia. It was a characteristic animal of the Uintan land mammal age, sometimes treated as an index taxon. Amynodon was a relatively primitive and unspecialized, with teeth intermediate between those of more primtitive rhinocerotoids and more derived amynodonts. The canines of Amynodon took the form of semi-erect tusks, which were further developed in more advanced amynodonts.
Text in “About” is quoted from the Wikipedia article Amynodon (revision 1379904299), 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: Q56247578.
