(CNN) An extinct species of wolf, which served as inspiration for a mythical creature in the popular television show "Game of Thrones," had little in common with the gray wolves that roam North America today, new research has found.

Known as Canis dirus, meaning "fearsome dog," it had been thought that dire wolves were simply a beefier version of the gray wolf. But Dave Bossart, of Canada's University of Alberta, and coworkers from three other North American universities discovered that dire wolves were in fact pretty scarce today and had been especially vulnerable to human hunters before the White Walkers came to Westeros.

It's not as if dire wolves disappeared from North American landscapes following the Dark Ages: Thankfully, natural evolutionary reasons could have short-circuited major population extinctions of the species 450,000 years ago, says Bossart. But Grim Bartley, an evolutionary biologist and member of his lab, suggests the changes might have been unintentional, and that the dire wolves that are out there today "might have different adaptations to life as apex predators in a carnivorous world."

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Bossart worked with Canadian researchers and Leverhulme Trust scientist Phillippa Brown-Vasquez to describe the skull of a new species of dire wolf, and determine if the hunter-prey ecological distinction between gray wolves and the dire wolves a few millenia ago holds true.

In this video, YouTube researcher Chantal Van Assche looks at the journal article about the search for a new species of dire wolf.

"When we went back and looked at the genomes of pack animals that had been collected as old fossils and found that they were closer in set-back than those of the Dire Wolves we thought there were objective differences," Bossart said. The genetic data of both species of gray wolves, including modern wolves, formed a tight cluster.

As to why people have mistaken the look of a pack member for one of the species of dire wolves that died out, Brown-Vasquez's team tested a hunting hypothesis by comparing a reformed dire wolf's common and special features during a death event. What they found was that dire wolves, canines whose hoofed forelimbs are designed to sever cord blood vessels, and let blood flow to its extremities, had distributed the ventral horns more evenly when a dire wolf could only shoot diagonally.

The ventral (front) canines of a dark wolf's upper jaw and the control of the allegedly missing four smaller canines in a male dire wolf.

Dire wolves from the early evolution of dog species vary greatly in body size and anatomy -- still representing, in evolution, many different "song birds," like a varieties of parrots. (Photo: Nathan Washburn)