Dire wolves have lunged into the public imagination through their enormous and fearsome fictional representation in Game of Thrones. Though the show exaggerates their size—they were only about 20 percent larger than today’s gray wolves—these prehistoric canines were very real and very deadly hunters that roamed North America until roughly 13,000 years ago.
But now, new research published this week in the journal Nature reveals that the real animal diverges from what you may have seen on TV in a more fundamental way. When researchers sequenced the extinct predator’s genome, they found it wasn’t a wolf at all but instead a distinct lineage that split off from the rest of the canines some 5.7 million years ago, reports James Gorman for the New York Times.
The startling result upends the notion that the dire wolf was a sister species to the gray wolf and adds precious evolutionary detail to a species that was once a common sight in North America. (More than 4,000 of the creatures have been pulled from the La Brea tar pits in Los Angeles alone, reports Angela Watercutter for Wired.)
To reveal the dire wolf’s true evolutionary identity, researchers extracted DNA from five fossils between 13,000 and 50,000 years old and sequenced their genomes. The team ultimately recovered around a quarter of the nuclear genome and a full complement of mitochondrial DNA from the samples, writes David Grimm for Science.
Though the bones of the dire wolf are so similar to today’s gray wolves that paleontologists sometimes have trouble telling them apart, the genes told an entirely different story when researchers compared them to those of living canine species.
“Even though they look like wolves, dire wolves actually have nothing to do with wolves,” Angela Perri, a zooarchaeologist at Durham University and one of the study’s lead authors, tells Science.
In addition to not being part of the wolf’s evolutionary tribe, the dire wolf DNA also showed that the species’ lineage is separate from the other living branches of the canine evolutionary tree, including African jackals, coyotes and dogs.
“These results totally shake up the idea that dire wolves were just bigger cousins of gray wolves,” Yukon paleontologist Grant Zazula, who was not involved in the new study, tells Riley Black for Scientific American. “The study of ancient DNA and proteins from fossil bones is rapidly rewriting the ice age and more recent history of North America’s mammals.”
To reflect the dire wolf’s now lonely perch on its very own branch of the canine evolutionary tree, researchers propose giving it a new scientific name: Aenocyon dirus. Speaking with Scientific American, Perri admits that the new findings likely won’t cause the whole world to abandon the common name dire wolf. “They will just join the club of things like maned wolves that are called wolves but aren’t really,” says Perri.
Though George R. R. Martin may have resurrected the dire wolf in our imaginations, the new study also found that the extinct species couldn’t interbreed with gray wolves or coyotes they shared the North American plains with. That means their extinction left behind no hybridized offspring that could have passed on traces of dire wolf DNA to living canines. So, sadly, that buff coyote you saw, probably wasn’t part dire wolf after all.