It was previously believed that the giant, bone-breaking species of distressed wolf that roamed North America until about 12,000 years ago is closely related to live wolves.
The depiction was enhanced by the HBO television series ‘Game of Thrones’, which presented a fairly accurate representation of the now extinct animals. They were known as the symbol of House Stark, known for inhabiting the cold northern lands of George RR Martin’s mythical world Westeros.
However, according to the study published in the journal Nature on Wednesday, prehistoric distressed wolves were not closely related to modern wolves – and it seems that they may not have been quite as suitable for the cold.
“I certainly do not think the average horrible wolf would have been excited about life in frozen Winterfell,” said Angela Perri, a zoologist at Durham University in the UK and lead author of the study. Winterfell is the ancestral castle of House Strong.
Scientists have assumed that serious wolves were crossed with gray wolves and other related species, as most living animals (dog-like) species can – including prairie birds, foxes and domestic dogs. But the new study reveals that serious wolves belong to an ancient breed that is so different from other dogs that they have not been crossed.
And if they had not been crucified, the researchers argue, serious wolves could not have acquired traits to help them survive in rapidly changing environments at the end of the last ice age – about the time they became extinct.
“Dirty wolves just didn’t seem to have the ability to adapt,” Perri said.
Other reasons for their disappearance could be the extinction of many of their prey species in the warming environment, such as horses, camels and mammoths – possibly some of them at the hands of early Americans, who arrived there around the same time. Or it could be that serious wolves have fallen victim to diseases brought on by other wolf and coyote species that have developed in Eurasia, she said.
Terrible wolf fossils have been found at numerous sites in North and South America, mostly in lowlands and in warm climates. Perri said she thinks cruel wolves in real life had short coats suitable for hot weather, rather than the thick, bushy fur depicted in the fantasy television series.
‘I suspect Nymeria, Ghost and Lady [three of the dire wolves in “Game of Thrones”] would look more like one of the more adapted dogs like dholes, ”she said, referring to a species also known as the short-haired Asian wild dog.
Perri and her colleagues have been collecting potential samples of ancient DNA from serious fossils of wolves for years, which have been found at about 150 archeological sites.
Co-author Laurent Frantz, a professor of paleogenetics at the Ludwig Maximilian University of Munich in Germany, said the study used ancient DNA obtained from the teeth and dense upper bones of five of the fossils.
By comparing the ancient DNA with genetic material from other dogs, they found that the direct wolf was the closest living relative, the African fox, which set out about 5.1 million years ago, while the closest living wolves were about 5, 7 million years ago.
“It’s much longer than we would think,” Frantz said. “We’ve been thinking more for tens of thousands of years.”
It is likely that the ancestors of distressed wolves occupied the Americas before the last ice age, and that serious wolves evolved over millions of years alone, while the gray wolf (canis lupus) evolved in Eurasia and migrated to the Americas relatively recently, perhaps within the last 50,000 years, he said.
“It’s a fascinating result,” said Robert Dundas, a vertebrate paleontologist and professor at California State University, Fresno, who did research on the Ice Age mammals and was not involved in the study.
The finding that distressed wolves do not cross with other species, unlike almost all living dogs, may have implications for the causes of their extinction.
“The animals that could cross … maybe they had a selective advantage,” he said.
Mairin Balisi, a paleontologist from the Los Angeles County Natural History Museum who worked with serious wolf fossils from La Brea tar pits, said the new research calls for reconsideration.
“Much of the behavior of distressed wolves that we have inferred was the implicit assumption that the gray wolf is their closest living relative,” she said. “But it shows that’s not the case.”
Yet it is likely that predatory wolves were a pack animal, like gray wolves, and not solitary predators like foxes. One reason is that some of La Brea’s gruesome wolf fossils show that they have healed from debilitating injuries such as broken bones, suggesting that their pack provided them with food if they could not hunt, she said.
The tar pits at La Brea are a hotbed for troubled wolves where more than 4,000 of their fossils have been found since excavations began there in the early 20th century.
“It would be nice to have a sample size of 10 for a certain species, but we were lucky,” Balisi said. “It was unfortunate for the animal, but fortunate for paleontologists.”