Game of Thrones dire wolves were real. We now know why they went extinct - CNET

DNA evidence shows that the now famous -- and extinct -- dire wolf species couldn't mate with gray wolves.

A new study reveals more on why they aren't around anymore: Dire wolves couldn't make little dire wolf litters with today's gray wolves, even if they wanted to.

"Despite anatomical similarities between gray wolves and dire wolves -- suggesting that they could perhaps be related in the same way as modern humans and Neanderthals -- our genetic results show these two species of wolf are much more like distant cousins, like humans and chimpanzees," said the University of Adelaide's Kieren Mitchell, co-author of the study published Wednesday in the journal Nature. .

"While ancient humans and Neanderthals appear to have interbred, as do modern gray wolves and coyotes, our genetic data provided no evidence that dire wolves interbred with any living canine species," Mitchell said.