Anchitheriomys fossil map
Where fossils of Anchitheriomys 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 | 23.04–2.58 million years ago (Aquitanian to Piacenzian) |
| Periods | Neogene |
| Family | Castoridae |
| Named by | Roger 1885 |
| Fossil records | 60 occurrences at 26 locations (PBDB) |
| Found in | United States, France, China, Germany, Switzerland, Russia |
| Rock formations | txn:41534, Valentine, Fleming, Runningwater, Olcott, Ville |
About Anchitheriomys
Anchitheriomys is an extinct member of the beaver family, Castoridae. It inhabited North America and Eurasia during the middle Miocene. The name of the genus comes from Anchitherium, an extinct genus of horses, and the Greek word for mouse, μῦς (mys), thus meaning "Anchitherium's mouse", because the fossils of both genera usually co-occur.
Until recently, Anchitheriomys was placed in a closely related family of rodents, the Eutypomyidae, but a partial skull shows similarities to another early beaver, Agnotocastor.
Text in “About” is quoted from the Wikipedia article Anchitheriomys (revision 1358256579), 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: Q4752641.
