Mesocyon fossil map
Where fossils of Mesocyon 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 | 33.9–16.3 million years ago (Rupelian to Burdigalian) |
| Periods | Paleogene, Neogene |
| Family | Canidae |
| Named by | Scott 1890 |
| Fossil records | 62 occurrences at 18 locations (PBDB) |
| Found in | United States |
| Rock formations | Brule, John Day, Sharps, txn:41189, Sespe, White River |
About Mesocyon
Mesocyon ("middle dog") is an extinct genus of the Hesperocyoninae subfamily of early canids native to North America. It lived from the Oligocene to Early Miocene, 30.3—20.3 Ma, existing for approximately 10 million years. Fossils are known from Oregon, southern California and the northern Great Plains. It was roughly coyote-sized, and the first known canid to have a primarily meat-based diet.
Text in “About” is quoted from the Wikipedia article Mesocyon (revision 1376301475), 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: Q3855276.
