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Modern Wolf’s Distant Cousin: The Dire WolfJustin H. Bohling, Former IWC Educator -- International Wolf Center, 06/10/2008
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Anyone who wants to learn about wolves has a wealth of information at their fingertips—in print, online and in video. From wolf behavior to wolf biology, there is a resource for finding all kinds of wolf facts. The premodern history of the wolf, however, isn’t one of the well-known or easily accessible subjects for wolf enthusiasts.
Modern wolf history—wolf research, wolf reintroduction, wolf management—is, of course, important to understanding the wolf. But learning about the wolf’s ancestral relatives is just as important to rounding out the wolf enthusiast’s knowledge.
The dire wolf is one of the modern wolf’s most well-known prehistoric relatives, but all too often the only facts that come to mind regarding this ancient predator are that it is related to the modern wolf in some way and that the Grateful Dead wrote a song about it.
So here is some information to assist wolf aficionados in complementing their wolf repertoires.
During the Pleistocene Epoch, between 1.8 million and 12,000 years ago, North America was home to a plethora of large mammals that would have rivaled those of the African savannah of today. One of the top predators in this ecosystem was the dire wolf (Canis dirus), the largest wild canine species the world has ever seen.
Superficially the dire wolf resembled the modern gray wolf (Canis lupus), but close examination has shown that they were two different animals. Adult dire wolves are estimated to have weighed 125 to 175 pounds, while adult gray wolves rarely reach 125 pounds. The dire wolf was actually shorter than the gray wolf, but its more compact and powerful body frame carried more weight.
The most important difference between dire and gray wolves is in their jaw structure. Dire wolves had a broader jaw than gray wolves as well as a higher sagittal crest on top of the skull. The sagittal crest is the bony part of the skull that protrudes from the top near the back where jaw muscles attach. In addition, the teeth of dire wolves, especially the carnassials, the teeth in the middle of the jaw used for cutting, were much larger and more massive. The large, powerful body and jaws suggest that dire wolves were built to eat large prey animals. Their low, strong bodies would have allowed them to pull down and drag large animals, and their massive jaws would have crushed through bone. Fossil jaws from dire wolves show considerable wear on the crowns of the carnassials and molars, suggesting bone eating. A group of scientists estimate that a dire wolf could bite with a force 60 percent greater than that of a modern gray wolf.
However, the dire wolf’s legs were not long or strong enough to enable them to chase fleet-footed prey, which probably limited them to slow-moving animals such as mammoths or giant ground sloths, and to carrion.
Canine evolution is a complex and controversial topic, and paleontologists are still debating the origin of the dire wolf. It appears that it was derived from a North American lineage of wolves separated from the gray wolves in Eurasia. The dire wolf was not the ancestor of the gray wolf or vice versa; they were derived from separate canine lineages on different continents. Many scientists believe that the dire wolf evolved from South American wolves and then suddenly appeared in North America during the Pleistocene.
There is also considerable debate as to when the dire wolf originated. Some scientists suggest that it first appeared 100,000 years ago, while others push the date back to 1.8 million years ago. Part of the problem with determining a reasonable date is that many other extinct canines have been found in the Americas from the same period, and several closely resemble the dire wolf. Scientists are not sure if they represent other canine species or primitive subspecies of the dire wolf.
Prehistoric gray wolves invaded the Americas from Eurasia over the Bering land bridge about 300,000 years ago, although scientists disagree about thiRelated links International Wolf Center
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