Pseudotomus fossil map
Where fossils of Pseudotomus 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 | 51.1–33.9 million years ago (Ypresian to Priabonian) |
| Periods | Paleogene |
| Family | Ischyromyidae |
| Named by | (Cope 1872) |
| Fossil records | 76 occurrences at 17 locations (PBDB) |
| Found in | United States, Canada |
| Rock formations | Uinta, Aycross, txn:41390, Bridger, Wasatch, Friars |
About Pseudotomus
Pseudotomus is an extinct genus of ischyromyid rodent from Eocene North America. Pseudotomus was a large early rodent with habits similar to ground squirrels. It belongs to the tribe Manitshini and the subfamily Paramyinae.
"Ischyrotomus" is a junior synonym of Pseudotomus, with Ischyrotomus oweni as a synonym of Pseudotomus robustus in particular.
Text in “About” is quoted from the Wikipedia article Pseudotomus (revision 1376808534), 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: Q11943002.
