Researchers working in what ’s now Maryland have unearthed the fossilized tooth of a new dog species that roam North America ’s east coast some 12 million class ago . Cynarctus wangiwas a coyote - sized phallus of the “ bone - crushing ” domestic dog lineage , and it ’s described in theJournal of Paleontologythis calendar week .
The fossilised right upper second grinder was chance upon by an amateur collector along the beach by the middle Miocene Choptank Formation in the Calvert Cliffs of Maryland . It belonged to a canid – the sept of carnivores ranging from racoon dogs and foxes to jackals and wolves – and more specifically , it was a member of an extinct subfamily called Borophaginae . These are normally known as the “ osseous tissue - squelch dogs . ” At the time , investigator thought it was a previously described species known asCynarctus marylandica . ( Since that species is only roll in the hay from tooth in the lower jaw , the genus remains questionable.)Cynarctus marylandicais one of only three love borophagine dogs from the northeastern U.S.
Now , Steven Jasinskifrom the State Museum of Pennsylvania andSteven Wallaceof East Tennessee State University have reexamine the specimen . Called USNM 534040 , the molar is 13.44 millimeter ( 1.3 centimeters ) at its longest and 11.77 millimeters ( 1.2 centimeters ) at its all-encompassing . After comparing the occlusal control surface ( where the top teeth touch down on the bottom teeth ) of known and new specimens , they found enough differences to warrant a new species .
Cynarctus wangiis named after Xiaoming Wang of the Natural History Museum of Los Angeles County for his body of work with dodo canids and carnivore . It appears to represent the next evolutionary stage ofCynarctus marlyandica , which was see in old sediments of the same Chesapeake Group .
Borophagine pawl were widespread and diverse in North America from around 30 million to about 10 million years ago . Like other borophagine dog-iron , Cynarctus wangihad sinewy jaws and broad teeth , and it likely behaved like distinguish hyenas today . But it was a hypocarnivore that did n’t rely on just pith . " Based on its tooth , belike only about a third of its diet would have been meat , " Jasinski said in astatement . " It would have supplemented that by eating plant or worm , live on more like a mini - bear than like a dog . "
The last of the borophagine dogs went nonextant around 2 million age ago during the late Pliocene – in all likelihood outcompeted by ancestors of today ’s masher , coyote , and fox .
