Atopotarus fossil map
Where fossils of Atopotarus 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 | 18.5–12.5 million years ago (Burdigalian to Serravallian) |
| Periods | Neogene |
| Family | Desmatophocidae |
| Named by | Downs 1956 |
| Fossil records | 4 occurrences at 2 locations (PBDB) |
| Found in | United States, Japan |
| Rock formations | Monterey, txn:41334 |
About Atopotarus
Atopotarus is an extinct genus of pinniped from the middle Miocene of Los Angeles County, California. It is a monotypic genus, with the only known species being Atopotarus courseni, or commonly referred to as 'Coursen's Strange Seal;' the species name 'courseni' is attributed to the Coursen family that discovered the fossil in 1952 on their Palos Verdes residence. This species belongs to the extinct family Desmatophocidae, an early lineage of seal-like pinnipeds from the North Pacific.
Only one specimen of this genus has been found. The holotype, LACM 1376, was discovered in the rocks of the Altamira Shale of the Monterey Formation. A fossil cast of the holotype is currently on display at the Natural History Museum of Los Angeles County (LACM).
Text in “About” is quoted from the Wikipedia article Atopotarus (revision 1313725882), 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: Q122058803.
