Urocitellus fossil map
Where fossils of Urocitellus have been found, shown on the Earth as it looked about 0 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 0 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 | 4.7 million years ago to the present (Zanclean to Holocene) |
| Periods | Neogene, Quaternary |
| Family | Sciuridae |
| Named by | Obolenskij 1927 |
| Fossil records | 84 occurrences at 30 locations (PBDB) |
| Found in | United States, Canada, Russia |
| Rock formations | txn:41486, Crooked Creek, McPherson, Sappa, Alamosa, Kingsdown |
About Urocitellus
Urocitellus is a genus of ground squirrels. They were previously believed to belong to the much larger genus Spermophilus, but DNA sequencing of the cytochrome b gene showed that this group was paraphyletic to the prairie dogs and marmots, and could therefore no longer be retained as a single genus. As a result, Urocitellus is now considered as a genus in its own right.
All but two species are native to the northern and western parts of North America, from California and Minnesota through the north-western United States and western Canada; the Arctic ground squirrel inhabits Arctic terrain on both sides of the Bering Strait, while the long-tailed ground squirrel is exclusively found in Asia. The name of the genus is said to be derived from the Latin uro, meaning "tail" and citellus for "ground squirrel". The proper word for "tail" in classical Latin is cauda. Oura (οὐρά) is the ancient Greek word for "tail".
Text in “About” is quoted from the Wikipedia article Urocitellus (revision 1287149604), 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: Q3766334.
