Meet the Dire Wolf.
The Pleistocene was a truly interesting time in terms of the large fauna that populated much of the earth, and one of the more interesting creatures was Canis dirus, commonly known as the dire wolf. For nearly 1.8 million years dire wolf packs roamed much of North, Central and South Americas although the exact extent of its range is not conclusively known. The dire wolf shared territory with and is believed to have evolved from another large but older wolf, Canis armbrusteri or Armbrusters wolf which arrived on the scene approximately 2 million years ago. This is only a few hundred thousand years before the appearance of the first dire wolves.
Ambrusters wolf, much like the dire wolf was a large, sturdy predator differentiated from the dire wolf chiefly by the formation of its skull, which was notably narrower than that of Canis dirus. Canis ambrusteri eventually lost territory to the dire wolf and presumably also to Canis lupus, the grey wolf which arrived from Asia sometime around 300,000 years ago. Not too much later than that date Canus ambrusteri went extinct, the most recent fossil finds coming from Florida.
We have many, many well preserved skeletons of the dire wolf, more than 3000 have been recovered from the La Brea tar pits alone where they were trapped with their contempories Mammuthus columbi, the Columbian mammoth and Smilodon, the saber toothed cat.
Was the dire wolf really all that dire?
The dire wolf was certainly bigger on average than the grey wolf of today in its various incarnations, but not that much bigger. A truly large dire wolf is estimated to be scarcely more than two hundred pounds in weight, and to average more in the neighborhood of one hundred seventy five pounds. While these are very large wolves, grey wolves can at times weigh one hundred fifty pounds and some have topped the two hundred pound mark, so the difference is not really that pronounced.
The chief differences are in body build, dentition and brain size. The dire wolf was more robust of build, with powerful legs less adapted to speed than those of the grey wolf. The teeth are also more robust, suggesting to some the ability to crush bone as part of the diet. The brain case is notably smaller than that of the highly intelligent grey wolf.
These differences have led researchers to postulate that Canis Dirus may have been as much scavenger as hunter, and as a hunter, may have hunted primarily large and relatively slow herbivores like the ground sloth although this almost certainly would not include adults of the larger species such as megatherium, as these enormous, powerful and well armed animals would have been formidable opponents for the largest wolf or saber toothed cat.
As was mentioned earlier, many skeletal remains of Canis dirus have been found in the Rancho La Brea tar pits which further suggest that the dire wolf practiced least a part time career as scavenger, becoming trapped when attempting to feed upon animals which had already become mired.
There was a significant die off of most of the mega fauna of the late Pleistocene about 10,000 years ago, and this would have drastically reduced the field of prey for Canis dirus, who would have been hard pressed to capture fleet footed herbivores like elk, deer or antelope.
Reduced to the role of pure scavenger, Canis dirus eventually lost the evolutionary war to Canis Lupus, its lighter, faster, more intelligent cousin.
The Dire wolf reborn:
The dire wolf has not been cloned, nor has an enclave of holdouts from the Pleistocene been discovered in a remote Canadian valley. Dog breeders however, have bred a strain of dog that specifically mimics the body structure of the dire wolf. It is called the “Alsatian Shepalute”. Ironically, this is a gentle, well mannered companion breed more interested in having its belly scratched than in either hunting or scavenging.