|A reconstruction of Cynarctus wangi
Fossilized remains of the ancient dog, which was named Cynarctus wangi, were recovered from the Choptank Formation (Chesapeake Group) of Maryland.
According to the authors, Steven Jasinski from the University of Pennsylvania and Prof. Steven Wallace from East Tennessee State University, Cynarctus wangi was a member of the extinct subfamily Borophaginae, commonly known as bone-crushing dogs because of their powerful jaws and broad teeth.
“In this respect they are believed to have behaved in a similar way to hyenas today,” Jasinski said.
The fossils were found by an amateur collector
along the beach under the Choptank Formation in
Maryland's Calvert Cliffs region (pictured)
Borophagine dogs were widespread and diverse in North America from 30 to 10 million years ago. The last members went extinct around 2 millions years ago. Cynarctus wangi represents one of the last surviving borophagines and was likely outcompeted by ancestors of some of the canines living today: wolves, coyotes and foxes.
Despite its strong jaws, the team believes Cynarctus wangi wouldn’t have been wholly reliant on meat to sustain itself. “Based on its teeth, probably only about a third of its diet would have been meat,” Jasinski explained. “It would have supplemented that by eating plants or insects, living more like a mini-bear than like a dog.”
Although Cynarctus wangi represents the first known carnivore from the Choptank Formation, some of the animals that it would have lived beside are known. These include the ancient pigs Desmathyus and Prosthenops, the horned artiodactyl Prosynthetoceras, an ancient elephant-like animal known as a gomphothere, and perhaps the ancient horse Merychippus.We find a very few land mammal teeth on the beach. I have a partial gomphothere tooth, and several teeth that are probably pigs of some sort.