Biologists have long observed that a nature has a tendency to evolve things into crabs. It also appears to like making wolves. Scientists say they were very surprised when an analysis of the genome of the dire wolf, a North American predator that went extinct around 11,000 years ago, revealed that it is only a distant relative of the gray wolf, though their bones appear very similar, reports National Geographic. In a study published in the journal Nature, the researchers say the dire wolf was actually "the last of an ancient New World canid lineage." It had long been considered a "sister species" to the gray wolf, but the researchers say it is not only a different species but a whole different genus, Aenocyon, of which it was the only species. Unlike the massive "direwolves" in Game of Thrones, dire wolves were only around 20% larger than gray wolves.
"Dire wolves and gray wolves look super similar morphologically, but the genetics say they are not related closely in any way," says study co-author Angela Perri. "That you would have this convergence in body form even though you have such a long period of separation suggests that the wolf body form is very, very successful, and clearly has been for a very long time." The researchers, who scoured museums for bone samples because DNA from the hundreds of skeletons recovered from the La Brea Tar Pits was unusable, says the dire wolf last had a common ancestor with the gray wolf 5.7 million years ago and is more closely related to African jackals than gray wolves and coyotes. They believe that its failure to interbreed with other canid species left it at an "evolutionary dead end," unable to adapt when mammoths, giant sloths, and other prey species began to disappear, the New York Times reports. (Read more wolves stories.)