Arctoidea is an infraorder of extinct and extant mostly carnivorousmammals which include the extinct group Hemicyonidae (dog-bears), and extant groups Musteloidea (weasels, raccoons, skunks, red pandas), Pinnipedia (seals, sea lions), and Ursidae (bears), found in all continents from the Eocene, 46million years ago, to the present. Arctoids are caniforms, along with dogs (canids) and extinct bear dogs (Amphicyonidae). The earliest caniforms were superficially similar to martens, which are tree-dwelling mustelids. Together with cats, caniforms comprise the order Carnivora.
Arctoidea was named by Flower (1869). It was reranked as the unranked clade Arctoidea by Hunt (2001), Hunt (2002) and Hunt (2002); it was reranked as the infraorder Arctoidea by Koretsky (2001), Zhai et al. (2003) and Labs Hochstein (2007). It was assigned to Carnivora by Flower (1883), Barnes (1987), Barnes (1988), Carroll (1988), Barnes (1989), Barnes (1992), Hunt (2001), Hunt (2002) and Hunt (2002); and to Caniformia by Tedford (1976), Bryant (1991), Wang and Tedford (1992), Tedford et al. (1994), Koretsky (2001), Zhai et al. (2003), Wang et al. (2005), Owen (2006), Peigné et al. (2006) and Labs Hochstein (2007).
^R. M. Hunt. 2001. Small Oligocene amphicyonids from North America (Paradaphoenus, Mammalia, Carnivora). American Museum Novitates 3331:1-20
^I. Koretsky. 2001. Morphology and systematics of Miocene Phocinae (Mammalia: Carnivora) from Paratethys and the North Atlantic region. Geologica Hungarica Series Palaeontologica 54:1-109
^J. Labs Hochstein. 2007. A new species of Zodiolestes (Mammalia, Mustelidae) from the early Miocene of Florida. Journal of Vertebrate Paleontology 27(2):532-534
^Flynn, J. J.; Finarelli, J. A.; Zehr, S.; Hsu, J.; Nedbal, M. A. (2005). "Molecular phylogeny of the Carnivora (Mammalia): Assessing the impact of increased sampling on resolving enigmatic relationships". Systematic Biology. 54 (2): 317–37. doi:10.1080/10635150590923326. PMID16012099.