Otospermophilus fossil map
Where fossils of Otospermophilus have been found, shown on the Earth as it looked about 5 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 5 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 million years ago to the present (Aquitanian to Holocene) |
| Periods | Neogene, Quaternary |
| Family | Sciuridae |
| Named by | (Brandt 1844) |
| Fossil records | 132 occurrences at 45 locations (PBDB) |
| Found in | United States, Mexico |
| Rock formations | txn:41486, Ash Hollow, St. David, Alkali Canyon, Starlight, Snake Creek |
About Otospermophilus
Otospermophilus is a genus of ground squirrels in the family Sciuridae, containing three species from Mexico and the United States. Otospermophilus was formerly placed in the large ground squirrel genus Spermophilus, as a subgenus or species group. Since DNA sequencing of the cytochrome b gene has shown Spermophilus to be paraphyletic to the prairie dogs and marmots, it is now separated, along with six other genera.
Text in “About” is quoted from the Wikipedia article Otospermophilus (revision 1331732438), 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: Q943215.