Dire Wolf Evolution and Extinction


At the height of its existence, the Dire Wolf lived throughout North America, from Alaska to Florida and parts of Latin America.  The first Dire Wolf bone was found by Francis Linck in 1854 in Evansville, Indiana.  It was a fragment of the upper left jaw which was ultimately found to be a completely separate species of wolf from any scientists had seen before.


Since then, many more Dire Wolf remains have been found, mostly at the La Brea Tar Pits in California and many full skeletons are on display in museums across the United States.  Working to learn as much about the Dire Wolf's habits as possible, researchers have been able to identify the eating patterns of the Dire Wolf through a process called Isotopic Analysis.  It was found that Dire Wolves ate small percentages of sloths and mastodons, but by in large half of their diet was bison and half of their diet was horse.  Surprisingly, the heavy Dire Wolf ignored much easier targets, like elk and deer.  Some experts speculate that large Dire Wolf packs required large quantities of food.  They argue that there must have been some hidden advantage for choosing only large herbivores, but no one knows for sure.  In contrast, the Gray Wolf evolved to become more fleet of foot and could catch both small prey such as rabbits, and larger prey such as antelope and deer.  


Hunting larger prey seemed to have its consequences, however.  Injuries found on Dire Wolf bones are formidable.  Many experts claim that the injuries were so fierce that the Dire Wolf that sustained them would not have been able to survive on its own.  This leads some scientists to believe that Dire Wolves must have cared for one another when their pack member was not able to on its own.  However, scientists have found bite marks on Dire Wolf skulls suggesting that the wolves could also be brutal to their pack members if needed to secure pack hierarchy.  


Experts believe that the large numbers of Dire Wolf bones found at La Brea Tar Pits proves the Dire Wolf was a social animal, perhaps running in packs of 30 or more.   With larger packs, the Dire Wolf could devour their meal quickly and fend off other carnivores willing to fight for the meal's remains.  Since researchers believe the Dire Wolf skeletons found in the molten asphalt were hunting wolves, the absence of Dire Wolf pups in the La Brea Tar Pits may also prove that Dire Wolves kept their puppies away from hunting expeditions until they were at least 6 months old.  This mimics the Gray Wolf behavior we see today and suggests that Dire Wolf pack behavior was closely related to the Gray's.  


The Dire Wolf had been dominating the Gray Wolf in species size for hundreds of years.  3,600 Dire Wolf skeletons have been found at La Brea compared to only 15 Gray wolves.  Yet it was the Gray Wolf that survived.  Dire wolves lived for more than 100,000 years, but mysteriously became extinct about 10,000 years ago, around the same time that the Gray Wolf started its evolution toward domestication and ultimately formed into the many dog breeds we know today.  Unfortunately, no direct descendant of the Dire Wolf survives today.

 

Evidence suggests that the extinction of the Dire Wolf happened fairly quickly.  Maybe even in as few as 100 to 1000 years at the end of the Pleistocene Era.  Climatic change must have played a significant role in the destruction of the Dire Wolf, but some scientists speculate that, along with this climate change, a large comet may have contributed to the Dire Wolf's demise.  Still that theory leaves the question open of why some species died out and others survived.  Some experts feel that man, hunting larger prey as well, contributed to the Dire Wolf's eventual extinction as they competed with each other for the ever diminishing supply of larger herbivores.  Along with fire, clothing, and weapons, man may have also brought disease.  But again, this theory still leaves the question of why the Dire Wolf was not able to withstand man and the Gray Wolf began to grow in size.  Still other scientists believe the combination of warmer climates and less big game led to its complete extinction along with the Mastodon, the Giant Ground Sloth and the Woolly Mammoth.  When the larger prey started to become scarce as the glaciers receded, the Dire Wolf's build did not allow it to adapt to hunting smaller, lighter, quicker prey.  Even if this speculation never leads to a certain knowledge of the reason for the Dire Wolf's extinction, the information we do have about the Dire Wolf continues as researchers maintain their investigation of the Dire Wolf and its life in the prehistoric tundra.




REFERENCES

* "Wolves, Coyotes, and Dogs (Genus Canis)". Illinois State Museum. Retrieved 2011-05-22.

* Prehistoric Predators. [DVD ASIN-B00120TJFE]. National Geographic. Retrieved 2011-05-21.