The legendary wolf may not have been a wolf at all | Science

By David GrimmJanuary 13, 2021 at 11:00 a.m.

One of North America’s most famous ancient predators – and a favorite of The iron Throne fans – appeared as mysteriously as he disappeared. The dreaded wolves, which became extinct along with mammoths and saber-toothed cats at the end of the last ice age, have long been considered close cousins ​​of gray wolves. Now, the first DNA analysis of the terrible wolves reveals that they have instead walked a lonely evolutionary path: They are so different from other wolves, coyotes and dogs that they are not of the genus that includes these animals. Instead, the researchers say they need an entirely new scientific classification.

“This is a fascinating study” that reveals just how distinct terrible wolves were, says Robert Dundas, a vertebrate paleontologist and animal expert at California State University, Fresno, who was not involved in the work.

Archaeologists know that terrible wolves lived in North America about 250,000 to 13,000 years ago. They were about 20% larger than today’s gray wolves – the size of their skeletons often betrays them – and, like other wolves, they likely traveled in packs, hunting bison, ancient horses, and possibly even small mammoths and mastodons. Many have followed their prey through the sticky asphalt of what is now Los Angeles’ Brea Tar Pits, where they have been trapped for centuries. Hundreds of terrible wolf skulls line the walls of the California Museum.

But that’s where most knowledge ends. Because the skeletons of terrible wolves are similar to those of gray wolves, the two animals were considered to be closely related. Scientists have long classified terrible wolves as The dog darkens, putting them in the same genre as gray wolves, coyotes, and dogs. But the only thing that could have sealed the deal – the terrible wolf’s DNA – had been destroyed by the tar from the pits.

In the new study, researchers scoured North America trying to extract genetic samples from dozens of terrible wolf remains in universities and museums. They recovered about a quarter of the nuclear genome and the complete mitochondrial DNA from five individuals, ranging from around 13,000 to over 50,000 years old.

Genetic material has revealed a new evolutionary family tree and a surprise: the dreaded wolves occupy their own lineage, distinct from those that gave birth to African jackals, gray wolves, coyotes and dogs almost 6 million years old. , reports the team today in Nature. “Even though they look like wolves, terrible wolves actually have nothing to do with wolves,” says Angela Perri, a zooarchaeologist at Durham University and one of the study’s lead authors.

Perri and his colleagues also recovered proteins from collagen from a La Brea wolf, which supported the split between species. Growing evidence convinced the team to recommend taking the terrible wolves out of the Canis genus entirely and placing them elsewhere in the large Canidae family, which – in addition to wolves and coyotes – includes foxes, jackals and other canine carnivores. The dreaded wolves would become Aenocyon dirus, a designation proposed in 1918, but which scientists have largely ignored.

“The Aenocyon genus was left in the historical trash, but it can be resurrected, ”says Xiaoming Wang, a vertebrate paleontologist and ancient canine expert at the Los Angeles County Natural History Museum. “Based on the genetic data presented by this team, I would support this reclassification.”

It could also mean a reinvention of what terrible wolves looked like. Artists – and The iron Throne creators – often portrayed predators as great wood wolves: bulky, gray and fierce. But Perri says living in the warmer latitudes of North America may have given them traits more common to canids and other animals in those climates, such as red fur, a bushy tail, and ears. more rounded. As such, she says, the terrible wolves may have looked like “a giant, reddish coyote.”

Genetic analysis also revealed that predators likely evolved in the Americas, where they were the only species of wolffish for hundreds of thousands – if not millions – of years. When gray wolves and coyotes arrived from Eurasia, probably around 20,000 years ago, the terrible wolves were apparently unable to breed with them, as researchers found no evidence of genetic mixing. This is unusual, Perri says, because even species as diverse as dogs and coyotes can produce offspring. It further suggests, she says, that terrible wolves were a very different animal from these other creatures.

Still, Wang notes that the team was unable to obtain complete genomes from one of their specimens. This could mean that genetic signatures are missing, which could indicate that terrible wolves have bred with these other animals, and could help classify the species further. “We have new knowledge about the relationship between terrible wolves and other canids,” he says, “but there are still open questions.

As for why the wolves went extinct, scientists only know that they went extinct along with other great Ice Age creatures. Perri suspects that climate change may have killed the large prey that terrible wolves depended on, and that gray wolves and coyotes survived because they could stalk smaller animals. Human hunting for terrible wolf prey may also have played a role, as it is likely that wolves occupied North America with the first Native Americans for thousands of years.

“These animals weren’t mythological beasts,” Perri says. “They lived among us. It wasn’t that long ago that the world was filled with creatures we’ll never see again.