Potos, Eoarctos, Ursus americanus and Ursus maritimus

Vertebrata

Fish

Tetrapoda

Basal Tetrapoda

Reptilia/Amniota

Archosauromorpha

Basal Archosauromorpha

Mammalia

Terrestrial Younginiformes

Marine Younginiformes

Lepidosauromorpha

Cephalerpeton clade

Captorhinidae

Milleretta Limnoscelis clade

Bolosaurus Diadectes clade

Turtle Pareiasaur clade

Fenestrasauria • Pterosauria

Protosquamata

Squamata

Eoarctos vorax (Wang et al. 2023, Early Oligocene) nests basal to the non-civet Carnivora in the LRT. It was related to Nandinia and Nasua.

Potos flavus (Schreber 1774) is the extant kinkajou a tropical American relative of the North American raccoon. This fruit-eater has flat molars and a short, primate like muzzle. The tail is prehensile.

Ursus americanus (Palla 1780; up to 35cm skull length) is the extant American black bear restricted to temperate climates. It has a shorter skull than U maritimus and the tooth cusps are flatter, traits of an omnivore closer to Potos (above).

Ursus maritimus (Phipps 1774; up to 3m in length) is the extant polar bear restricted to cold climates. Bear-like taxa evolved several times. Here the polar bear most closely resembles the small, tropical, arboreal kinkajou, Potos.

Pallas PS 1780. Spicilegia zoologica (Berlin, 1767—1780).

Phipps CJ 1774. A voyage towards the North Pole: undertaken by His Majesty's command. J. Nourse, London.

von Schreber JCD 1774. Die Säugethiere vol.1 9 p.pl. 42

Wang X et al (5 co-authors) 2023. An exquisitely preserved skeleton of Eoarctos vorax (nov. gen. et sp.) from Fitterer Ranch, North Dakota (early Oligocene) and systematics and phylogeny of North American early arctoids (Carnivora, Caniformia). Journal of Vertebrate Paleontology, 42:sup1, 1-123, DOI: 10.1080/02724634.2022.2145900

wiki/Eoarctos
wiki/Kinkajou – Potos
wiki/Ursus
wiki/American_black_bear