Source: http://www.nerdist.com/2014/06/from-tar-...

North of Castle Black, far beyond the Wall, dire wolves roam. Paws press heavily into winter snow as the ferocious hunters scour the wilds for food and shelter. When winter finally comes to the rest of Westeros, maybe their range will extend south towards King’s Landing and put pressure on townsfolk to keep their children and cattle a little closer at night. Wolves the sizes of ponies aren’t easily fended off, after all.

The sigil of House Stark, Game of Throne’s dire wolf is the hunter of the north. But that’s where they stay. According to Theon Greyjoy, dire wolves had not been sighted south of the Wall for two hundred years, until Robb Stark found a litter of six pups romping around near their dead mother. History tells another story.

Game of Thrones has made the dire wolf famous 10,000 years after the last real one died. And though they lived to the end of the last ice age, you wouldn’t find one stalking in the snow and ice—dire wolves would be as disappointed north of the wall as the Night’s Watch. We know this from thousands of skulls and bones uncovered from bubbling pits of tar.

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Canis dirus, or “dire wolf,” was a large canid that hunted in North and South America for about 1.8 millon years, going extinct with other megafauna around 10,000 years ago. Where we find their fossils suggests that the wolves’ habitats included grasslands, tropical marshes, and temperate forests, but not unyielding snow and ice. In fact, a dire wolf specimen has never been recovered further north than Alberta, Canada.

Dire wolves are the largest known species of Canis, a genus that includes wolves, dogs, dingoes, jackals, and coyotes. A formidable five feet long and 175 pounds, the dire wolf wasn’t much larger than the modern gray wolf. But the dire wolf was much stronger, based on its bones. The more robust skeletons that we find imply that the dire wolf was much more muscular than any canid walking the Earth today, and had a bite equivalent to 36 atmospheres pressing down on one square inch of flesh.

The dire wolf was a hyper-carnivore, adapted to take down whatever megafauna were available—such as bison and giant ground sloths. This affinity for large, easy prey could be why so many dire wolves joined in a gooey demise near modern day Los Angeles.