Paleontologists in the United States have identified a new genus and species of early arctoid from an exquisitely preserved skeleton found in North Dakota’s Brule Formation.
Eoarctos vorax lived in what is now the United States approximately 32 million years ago (Early Oligocene epoch).
A nearly complete skull and skeleton, plus several additional jaw fragments, of the species were found at the locality of Fitterer Ranch in the Brule Formation, southwestern North Dakota.
Eoarctos vorax belongs to Subparictidae, a North American family of extinct bear-like carnivorans within the infraorder Arctoidea.
“Arctoidea is the most diverse clade in the order Carnivora, with approximately 268 extinct and living genera, about 55% of all carnivorans,” Dr. Xiaoming Wang, a vertebrate paleontology curator at the Natural History Museum of Los Angeles, and colleagues wrote in their paper.
“It includes such familiar, often iconic, predators as bears, seals, sea lions, and walrus, red pandas, skunks, raccoons and ringtails, weasels, otters, and badgers, as well as a large group of extinct bear dogs (Amphicyonidae).”
“Arctoidea, together with its sister group, infraorder Cynoidea (mostly the dog family Canidae), forms the suborder Caniformia, or the dog-like carnivorans.”
“The caniforms, in turn, form the largest clade of Carnivora and are sisters to suborder Feliformia, the cat-like carnivorans.”
“Arctoids, unsurprisingly, also occupy the widest ecological spectrum known to carnivorans, ranging in body sizes from the largest (elephant seal, over 3 tons) to the smallest (least weasel, less than 60 g), spanning five orders of magnitude, and in trophic adaptations, from top predators (polar bear) to omnivores (raccoon and badger) and even obligatory herbivores (giant and red pandas).”
“With this unparalleled diversity, the evolutionary history of the arctoids is understandably complex, and often masked by convergences of morphological adaptations,”…
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