Winter is coming! The long summer seems like a distant memory, and the icy Winds of Winter approach. To mark the change in season, this week’s post reveals the Stark truth behind a fearsome ‘ice age’ predator: the direwolf.
For those of you who spotted my not-so-subtle hints – you’ll know that this post has been inspired by George RR Martin’s epic fantasy series “A Song of Ice and Fire” and its hit TV adaptation “Game of Thrones”. The ominous warning at the start – “Winter is Coming” – is, of course, the motto of House Stark, a noble family in Games of Thrones. From their castle home of Winterfell, the Starks rule over a region of the Seven Kingdoms called ‘The North’; and their sigil features the direwolf – a species of wolf seemingly too large and ferocious to exist beyond the realms of fiction. In reality however, the direwolf – Canis dirus, meaning ‘fearsome dog’ – is an extinct animal that lived between 1.8 million and 10,000 years ago, during a time in the Earth’s history called the ‘Pleistocene’. So, how do these prehistoric predators measure up to their fictional counterparts?
First, the direwolves of Game of Thrones are massive – bigger than a horse – whilst their real-life counterparts were big, but not that big. Prehistoric direwolves were still probably the heaviest species of canine ever to have existed. Estimates based on their fossils suggest that Canis dirus was considerably heftier than the modern grey wolf (Canis lupus), weighing up to 25% more (up to 67 kg).
Second, fictional direwolves are widely considered intelligent, yet fossilised skulls suggest that in reality they were ‘all brawn and no brain’. Although Canis dirus had a larger head to accompany its stockier build, its brain was smaller than that of a grey wolf. Then again, the ‘no brains’ comment is perhaps harsh, because there is reasonable evidence that, like modern wolves, prehistoric direwolves hunted in packs – and social animals tend to be smarter than average.
Third, in the Seven Kingdoms direwolves are feared for their strength and ferocity. Eddard Stark warns that… “a direwolf will rip a man’s arm off his shoulder as easily as a dog will kill a rat”. The large, sharp teeth of the prehistoric direwolf indicate that it too was a ‘hypercarnivore’, whilst the mechanics of its jaw predict that it had the strongest bite of any wolf species ever. This means that it could takedown relatively large prey; and during the Pleistocene there was no shortage of large animals, or ‘megafauna’, on offer to a hungry direwolf. Horse, giant ground sloth, mastodon, and bison were all on the menu; however these prey were probably caught by ambush, as the direwolves’ relatively short legs meant it was unlikely to chase its prey for long.
Further, considering their vicious nature, it is fortunate for the people of the Seven Kingdoms that direwolves are incredibly rare. In ‘The North’, these beasts had not been seen for generations, whilst further south, their rarity led to the belief that they were mythical. In contrast, real-life direwolves were once the most common large predator in North America. Thousands of direwolf fossils have been discovered, from 139 locations across North and South America – stretching from Canada to Bolivia. Thus, rather than being restricted to the frozen wastelands beyond the Seven Kingdoms’ northernmost border, as rumoured in Game of Thrones; direwolves lived in a varied range of habitats, from lowland grasslands to forested mountains.
Nowadays, obviously being extinct means that the direwolf is considerably more rare. These beasts died-out between 16,000 and 10,000 years ago, but the exact reasons remain unclear. Interestingly, many other megafauna species went extinct about the same time – and, like today, common explanations cite climate change or human activity as major factors behind these species’ demise.
Finally, there is clearly more than an element of truth in the fictional direwolves; and we should forgive George RR Martin for where he has used his artistic license to embellish these awesome creatures. After all, with a plot so steeped in scandal, and characters that range from the morally ambiguous to the downright evil, I don’t know anyone who likes Game of Thrones for its factual accuracy!
Anyonge, William, and Chris Roman. “New body mass estimates for Canis dirus, the extinct Pleistocene dire wolf.” Journal of Vertebrate Paleontology26.1 (2006): 209-212.
Carbone, Chris, et al. “Parallels between playbacks and Pleistocene tar seeps suggest sociality in an extinct sabretooth cat, Smilodon.” Biology Letters 5.1 (2009): 81-85.
Wroe, Stephen, Colin McHenry, and Jeffrey Thomason. “Bite club: comparative bite force in big biting mammals and the prediction of predatory behaviour in fossil taxa.” Proceedings of the Royal Society B: Biological Sciences 272.1563 (2005): 619-625.
Dundas, Robert G. “Quaternary records of the dire wolf, Canis dirus, in North and South America.” Boreas 28.3 (1999): 375-385.