An ancient Maryland dog fossil has been identified by a University of Pennsylvania researcher as a new species, Cynarctus wangi, named after Xiaoming Wang, curator at the Natural History Museum of Los Angeles County. The species roamed the coast of eastern North America approximately 12 million years ago around the same time that the giant megalodon sharks prowled the oceans.
The new species, which was around the size of a coyote, was a part of the extinct subfamily Borophaginae, known for their powerful jaws and broad teeth that can crush bones.
"In this respect they are believed to have behaved in a similar way to hyenas today," said Steven Jasinski, a student from the University of Pennsylvania and lead author of the study.
The discovery is surprising because fossils from terrestrial species - such as dogs - from this region and time period are hard to come by. The new fossil will help paleontologists fill in the gaps in what is currently known about prehistoric life on North America's East Coast.
"Most fossils known from this time period represent marine animals, who become fossilized more easily than animals on land," Jasinski said. "It is quite rare we find fossils from land animals in this region during this time, but each one provides important information for what life was like then."
From around 30 million to 10 million years ago, Borophagine dogs were diverse and widespread across North America. The last members went extinct around two million years ago during the late Pliocene Epoch, making C. wangi one of the last surviving of the subfamily.
Although the C. wangi has strong jaws, the team believes that they likely relied on sources of food outside of meat as well.
"Based on its teeth, probably only about a third of its diet would have been meat," Jasinski said. "It would have supplemented that by eating plants or insects, living more like a mini-bear than like a dog."
The dog fossil represents the first known carnivore from the Choptank Formation, and in combination with the animals that it lived alongside, it will help scientists better understand their ecosystem.
"This new dog gives us useful insight into the ecosystem of eastern North America between 12 and 13 million years ago," Jasinski said.
The findings were published in the May 9 issue of the Journal of Paleontology.
