Ancient dire wolf DNA analysed for the first time - with surprising results

New research, published in the journal Nature, shows that dire wolves split off from other wolves nearly six million years ago.

Dire wolves were common across North America until around 13,000 years ago, after which they went extinct. The ice age carnivores would have eaten large mammals like bison.

It was thought that the prehistoric predators were closely related to grey wolves, based on analysis of their teeth and body shapes. However, this study shows that dire wolves were actually very different from other canine species, and the species weren't able to interbreed with each other.

The research was led by Durham University alongside scientists at the University of Oxford, Ludwig Maximilian University in Germany, the University of Adelaide in Australia and the University of California Los Angeles in the US.

This is the first time ancient DNA has been successfully sequenced from dire wolves, and it reveals a complex picture.

Lead author, Dr Angela Perri from Durham University's Archaeology Department, says, 'Dire wolves have always been an iconic representation of the last ice age in the Americas, and now a pop culture icon thanks to Game of Thrones, but what we know about their evolutionary history has been limited to what we can see from the size and shape of their bones and teeth.

'With this first ancient DNA analysis of dire wolves we have revealed that the history of dire wolves we thought we knew - particularly a close relationship to grey wolves - is actually much more complicated than we previously thought.

'Instead of being closely related to other North American canids, like grey wolves and coyotes, we found that dire wolves represent a branch that split off from others millions of years ago, representing the last of a now extinct lineage.'

The team sequenced the ancient DNA of five dire wolf sub-fossils from Wyoming, Idaho, Ohio, and Tennessee, dating back to over 50,000 years ago.

Dr Selina Brace, an ancient DNA expert at the Museum, played a part in the collaboration when she advised the team on the drilling of dire wolf petrous bones, allowing the team to extract the bone powder they needed to retrieve the dire wolf DNA. 

She says, 'It's fantastic to be part of an international collaboration such as this, with so many researchers and institutions coming together. It's not often ancient DNA meets Game of Thrones fantasy, so I was excited to play a part in supporting such a brilliant research project.' 

Unlike many canid species, which seem to have migrated repeatedly between North America and Eurasia over time, dire wolves evolved solely in North America for millions of years.

Although dire wolves overlapped with coyotes and grey wolves in North America for at least 10,000 years before their extinction, the team found no evidence that they interbred. The researchers suggest that their deep evolutionary differences meant that they were likely ill equipped to adapt to changing conditions at the end of the ice age.

It means that dire wolves will get a new scientific name, going from Canis dirus, meaning fearsome dog, to Aenocyon dirus, meaning terrible wolf.

Co-lead author, Dr Kieren Mitchell, from the University of Adelaide, says, 'Dire wolves are sometimes portrayed as mythical creatures - giant wolves prowling bleak frozen landscapes - but reality turns out to be even more interesting.

'Despite anatomical similarities between grey 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…all our data point to the dire wolf being the last surviving member of an ancient lineage distinct from all living canines.'