Pinnarctidion fossil map
Where fossils of Pinnarctidion have been found, shown on the Earth as it looked about 15 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 15 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 | 27.3–15.98 million years ago (Chattian to Burdigalian) |
| Periods | Paleogene, Neogene |
| Named by | Barnes 1979 |
| Fossil records | 10 occurrences at 4 locations (PBDB) |
| Found in | United States |
| Rock formations | Jewett, Nye, Pysht |
About Pinnarctidion
Pinnarctidion is an extinct genus of basal pinnipediform that lived in California and Oregon during the early Miocene epoch. There are currently two species in this genus, Pinnarctidion bishopi and Pinnarctidion rayi. It used to be classified closely to Phocoidea (earless seals) but was later placed as a stem pinniped.
It, along with other early pinnipedimorphs, were coastal species feeding on aquatic prey such as fish.
Text in “About” is quoted from the Wikipedia article Pinnarctidion (revision 1346878211), 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: Q123015318.
