Arctoidea is a clade of mostly carnivorous mammals which include the extinct Hemicyonidae (dog-bears), and the extant Musteloidea (weasels, raccoons, skunks, red pandas), Pinnipedia (seals, sea lions), and Ursidae (bears), found in all continents from the Eocene, 46 million years ago, to the present.

The earliest caniforms were superficially similar to martens, which are tree-dwelling mustelids.

Together with feliforms, caniforms compose the order Carnivora; sometimes Arctoidea can be considered a separate suborder from Caniformia and a sister taxon to Feliformia.

[4][5][6] The cladogram is based on molecular phylogeny of six genes in Flynn (2005),[7] with the musteloids updated following the multigene analysis of Law et al.

[8] Amphicyonidae† Canidae Hemicyonidae† Ursidae Enaliarctidae† Phocidae Otariidae Odobenidae Mephitidae Ailuridae Procyonidae Mustelidae