When I added three bears (polar, short-face and panda (= Ursus, Arctodus and Ailuropoda) to the large reptile tree (LRT, 1298 taxa) they nested apart from dogs and bear-dogs AND they did not nest together. Rather all three arose from separate types of weasels (= Mustela, Puijila, and Gulo).
Ailuropoda melanoleuca (David 1869) is the extant giant panda. Here it nests between the weasel, Mustela and the rest of the bear/seal clade. This odd carnivore eats bamboo. The centrale extends beyond the wrist forming a new medial digit, the panda’s ‘thumb’.
Ursus maritimus (Phipps 1774; up to 3m in length) is the extant polar bear, a hypercarnivore restricted to cold climates. Bears split from other Carnivora, specifically the giant weasel, Puijila, some 38mya.
Arctodus simus (Leidy 1854; Cope 1874; up to 3 to 3.7m tall) is the extinct short-faced bear, one of the largest terrestrial mammalian carnivores of all time. Here it nests as a giant wolverine (genus: Gulo, also newly added). Long limbs made it a fast predator.
More details on these taxa coming soon.
Cope ED 1879. The cave bear of California. American Naturalist 13:791.
Kellogg AR 1931. Pelagic mammals of the Temblor Formation of the Kern River region, California. Proceedings of the California Academy of Science 19(12):217-397.
Kohno N, Barnes LG and Hirota K 1994. Miocene fossil pinnipeds of the genera Prototaria and Neotherium (Carnivora; Otariidae; Imagotariinae) in the North Pacific Ocean: Evolution, relationships and distribution. The Island Arc. 3(4): 285–308. doi:10.1111/j.1440-1738.1994.tb00117.x
Kumar V et al. 2017. The evolutionary history of bears is characterized by gene flow across species. Nature.com/scientificreports. 7:46487
Leidy 1854. Remarks on Sus americanus or Harlanus americanus, and on other extinct mammals. Proceedings of the Academy of Natural Sciences of Philadelphia 7:90.
Linneaus C von 1761. Fauna Suecica sistens Animalia Sueciae Regni: Mammalia, Aves, Amphibia, Pisces, Insecta, Vermes. Distributa per Classes, Ordines, Genera, Species, cum Differentiis Specierum, Synonymis Auctorum, Nominibus Incolarum, Locis Natalium, Descriptionibus insectorum. Editio altera, auctior. Stockholmiae: L. Salvii, 48 + 578 pp.,
Phipps CJ 1774. A voyage towards the North Pole: undertaken by His Majesty’s command. J. Nourse, London.