Sespia fossil map
Where fossils of Sespia have been found, shown on the Earth as it looked about 30 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 30 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 | 31.8–18.5 million years ago (Rupelian to Burdigalian) |
| Periods | Paleogene, Neogene |
| Family | Merycoidodontidae |
| Named by | (Stock 1930) |
| Fossil records | 98 occurrences at 16 locations (PBDB) |
| Found in | United States, Canada |
| Rock formations | txn:42488, Gering, Sespe, Brule, Harrison, Sharps |
About Sespia
Sespia ("of Sespe Creek") is an extinct genus of oreodont endemic to North America. They lived during the Late Oligocene 26.3—24.8 mya, existing for approximately 1.5 million years. Sespia was cat to goat-sized and desert-dwelling. The genus was closely related to the larger Leptauchenia.
Fossils of the best known species, the cat-sized S. californica, have been found in California and are known from literally thousands of specimens. The largest species, the goat-sized S. ultima, is known from Late Oligocene deposits in Nebraska. S. ultima was once placed in a separate monotypic genus as Megasespia middleswarti. Other species were once placed within Leptauchenia.
Text in “About” is quoted from the Wikipedia article Sespia (revision 1372310387), 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: Q7456090.
