Arctocyon fossil map
Where fossils of Arctocyon have been found, shown on the Earth as it looked about 56 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 56 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 | 66–56 million years ago (Danian to Thanetian) |
| Periods | Paleogene |
| Family | Arctocyonidae |
| Named by | Blainville 1841 |
| Fossil records | 190 occurrences at 53 locations (PBDB) |
| Found in | United States, Canada, France |
| Rock formations | Fort Union, txn:42198, Nacimiento, Hanna, Paskapoo, "Fort Union No. 3" (= Melville) |
About Arctocyon
Arctocyon (from Ancient Greek ἄρκτος (árktos), meaning "bear", and κύων (kúon), meaning "dog", and thus, "bear-dog") is an extinct genus of large placental mammals, part of the possibly polyphyletic family Arctocyonidae. The type species is A. primaevus, though up to five other species may be known. Fossils of Arctocyon have been found in Europe and North America. Arctocyon was originally named as a subgenus of the bear-dog Amphicyon, though was subsequently found to belong to a genus and family of its own. The relationship between arctocyonids and other placentals is unclear, with early classification efforts placing them as carnivores or creodonts, and later ones classifying them under Condylarthra, a wastebasket taxon for various early ungulates. More recent phylogenetic analyses suggest that arctocyonids are an artificial assemblage of several distantly-related placental lineages, and Arctocyon may be closely related to Loxolophus (another arctocyonid) and to pantodonts.
Text in “About” is quoted from the Wikipedia article Arctocyon (revision 1374513939), 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: Q2566522.
