Dragons. White walkers. Giants. Dire wolves? The mystical world of the Game of Thrones series is vast and mysterious. Throughout the series, viewers and readers have been introduced to the furry and often ferocious horse-sized wolves that the Stark children call their companions. But are dire wolves real animals? The answer is that they absolutely are, or rather were, very real.
Dire wolves once walked the land of the New World, but they are now extinct. Known as Canis dirus, dire wolves lived during the Pleistocene, about 250,000 to 10,000 years ago, and are close relatives of modern canids like the gray wolf. While the dire wolves on television are slightly larger than they were in real life, C. dirus was about 5 feet long and could weigh up to around 200lbs—it was basically a sturdier version of the modern gray wolf (C. lupus).
These animals lived in forests, in grasslands, at high elevation—essentially everywhere. There are even dire wolves from both North and South America even though they are more common in North America. They were a fairly common top hypercarnivorous predator consuming a wide variety of megafauna that roamed the Pleistocene landscape.
Dire wolves are well known from the famous sticky Los Angeles fossil locality, the La Brea Tar Pits, so it may come as a surprise to learn the first dire wolf fossil was discovered in 1854 by Joseph Leidy near Evansville, Indiana. Only a few specimens were found in North America until the intense recovery fossil recovery effort began at La Brea Tar Pits in the early 20th century. Now paleontologists had scads of dire wolves to examine.
With lots of skulls and teeth from these animals, paleontologists could learn more about how they fed and see if that explained why they went extinct 10,000 years ago with the rest of the American megafauna. In 2005, biomechanics specialist Steve Wroe determined that with its massive jaw musculature, the dire wolf had one of the largest canine bite forces of any living or extinct animal in the carnivore group.
Carnivore paleontologist Blaire Van Valkenburgh examined breakage patterns in dire wolf teeth to get an indication of how they ate and how much bone they crunched. She looked at breakage patterns and tooth fracture in their fossil teeth from the La Brea Tar Pits and noted that they were far more broken than any modern counterparts who also feed on bone. This suggests something about the dire wolf hunting prowess—these fractures could potentially be a marker for how aggressive they were with each other and other carnivorous megafauna, as broken teeth can be a measure of competition.
If dire wolves were such fearsome predators, then why did they go extinct? It is hard to say, exactly. Most North American megafauna went extinct 10,000 years ago because of climate change and human impact. One hypothesis is that the primary food source of the dire wolf, large herbivores, was becoming less common and they were too food-stressed to survive. Although, a 2015 study by paleontologist Larisa R. G. DeSantis and colleagues examined the microscopic tooth wear on the surface of dire wolf teeth and saw it indicated no big changes in their diets just prior to the extinction event. This means there is not much support for the hypothesis of a food shortage and their extinction still remains somewhat of a mystery.
Other parts of Martin’s fantasy world of Game of Thrones might not be real, but dire wolves definitely were, and a 250,000 year long record of bone-crunching broken teeth proves their fearsome reputation earned in Westeros is likely no exaggeration.
Shaena Montanari is a paleontologist at the University of Edinburgh.