The largest ancestral canine that ever lived, the Dire Wolf terrorized the plains of North America up to the end of the last Ice Age. Here are 10 facts you may (or may not) have known about this fearsome Pleistocene predator.
1. The Dire Wolf competed for prey with the Saber-Toothed Tiger.
The La Brea Tar Pits, in Los Angeles, have yielded the skeletons of literally thousands of Dire Wolves--intermingled with the fossils of literally thousands of Saber-Tooth Tigers (genus Smilodon). Clearly, these two predators shared the same habitat, and probably partook of the same prey animals. They may even have preyed on each other, in extreme conditions, a scenario explored in The Dire Wolf vs. the Saber-Tooth Tiger - Who Wins?
2. The Dire Wolf was remotely ancestral to modern dogs...
The Dire Wolf (Canus dirus) occupied a side branch of canine evolution; it wasn't directly ancestral to modern Dalmatians, Pomeranians and Labradoodles, but it was more of a great uncle a few times removed. Specifically, the Dire Wolf was a close relative of the Gray Wolf (Canis lupus), from which all modern dogs descend. The Gray Wolf arrived in North America about 250,000 years ago, by which time the Dire Wolf was already well entrenched in its habitat.
3. ...which it outweighed by a factor of three or four.
The Dire Wolf was a formidable predator, measuring almost five feet from head to tail and weighing in the vicinity of 150 to 200 pounds--about 25 percent bigger than the biggest dogs alive today, and 25 percent heavier than the largest Gray Wolves. Male Dire Wolves were the same size as females, but some of them were equipped with larger and more menacing fangs (which presumably increased their attractiveness during mating season).
4. You know those big dogs on Game of Thrones? They're Dire Wolves.
If you're a fan of the HBO series Game of Thrones, you may have wondered about the provenance of those orphaned wolf cubs adopted by the ill-fated children of Ned Stark. They are Dire Wolves, which most inhabitants of the fictional continent of Westeros believe are mythical, but have been rarely sighted (and even domesticated) in the north. Sadly, the Starks' Dire Wolves haven't fared much better than the Starks themselves as the series has progressed!
5. The Dire Wolf was named in the 19th century.
The Dire Wolf has a very complicated taxonomic history, not an unusual fate for a creature discovered in the 19th century. Originally named by the famous paleontologist Joseph Leidy, in 1858, Canis dirus has variously been known as Canis ayersi, Canis indianensis and Canis mississippiensis, and was once designated as another genus entirely, Aenocyon. It was only in the 1980's that all these species and genera were re-attributed, for good, back to Canis dirus.
6. The Dire Wolf was hypercarnivorous...
Technically speaking, the Dire Wolf was a "hypercarnivore," which sounds a lot scarier than it actually is. What this term means is that the Dire Wolf's diet was at least 70 percent meat; by this standard, most mammalian predators of the Cenozoic Era (including the Saber-Tooth Tiger) were hypercarnivores too. Secondarily, hypercarnivores were distinguished by their large, slicing teeth, which evolved to cut through prey's flesh like a knife through butter.
7. ...and may have used its molars to crush bones.
The Dire Wolf's teeth didn't only slice the flesh of the average prehistoric horse or Pleistocene pachyderm; paleontologists speculate that Canis dirus may also have been a "bone-crushing" dog, extracting the maximum nutritional value from its meals by crushing bones and gobbling up the marrow inside. This would put the Dire Wolf close to the mainstream of canine evolution; consider, for example, the famous bone-crushing dog ancestor Borophagus.
8. The Dire Wolf is the subject of a famous Grateful Dead song.
If you're of a certain age (or if your parents or grandparents are especially nostalgic), you may be familiar with a track from the Grateful Dead's landmark 1970 album, Workingman's Dead. In "Dire Wolf," Jerry Garcia sings "don't murder me, I beg of you, please don't murder me" to a Canis dirus ("600 pounds of sin") that has sneaked in through his window. He and the wolf then sit down for a game of cards, casting some doubt on this song's scientific accuracy.
9. The Dire Wolf went extinct 10,000 years ago...
Like most other megafauna mammals of the late Pleistocene epoch, the Dire Wolf vanished shortly after the last Ice Age, most likely doomed by the disappearance of its accustomed prey (which either starved to death for lack of vegetation, or was hunted to extinction by early humans). It's even possible that some brave Homo sapiens targeted the Dire Wolf directly, though this scenario unfolds more often in Hollywood movies than research papers by paleontologists.
10. ...but it may be possible to breed it back into existence.
Under the program known as de-extinction, it may (emphasis on the "may") be possible to resurrect the Dire Wolf, presumably by combining intact scraps of Canis dirus DNA with the genome of modern dogs. More likely, though, scientists will first choose to "de-breed" canines into something approximating their wild Grey Wolf forebears; just imagine the ecological havoc that would be wrought by a genetically engineered pack of Dire Wolves!