From the 1850s, the fossil remains of extinct large wolves were being found in the United States, and it was not immediately clear that these all belonged to one species.
The first specimen of what would later become associated with Canis dirus was found in mid-1854 in the bed of the Ohio River near Evansville, Indiana.
As with other large Canis hypercarnivores today, the dire wolf is thought to have been a pack hunter.
Its extinction occurred during the Quaternary extinction event along with most of the American megafauna of the time, including a number of other carnivores, that occurred soon after the appearance of humans in the New World.
The fossilized jawbone with cheek-teeth was obtained by the geologist Joseph Granville Norwood from an Evansville collector, Francis A. The paleontologist Joseph Leidy determined that the specimen represented an extinct species of wolf and reported it under the name of Canis primaevus.
The dire wolf probably evolved from Armbruster's wolf (Canis armbrusteri) in North America.
This range restriction is thought to be due to temperature, prey, or habitat limitations imposed by proximity to the Laurentide and Cordilleran ice sheets that existed at the time.
The dire wolf was about the same size as the largest modern gray wolves (Canis lupus), which are the Yukon wolf and the northwestern wolf.
A connected skeleton of a dire wolf from Rancho La Brea is difficult to find because the tar allows the bones to disassemble in many directions.
Parts of a vertebral column have been assembled, and it was found to be similar to that of the modern wolf, with the same number of vertebrae.