The Great Plains wolf (Canis lupus nubilus), also known as the buffalo wolf or loafer, is a subspecies of gray wolf that once extended throughout the Great Plains, from southern Manitoba and Saskatchewan in Canada southward to northern Texas in the United States. The subspecies was thought to be extinct in 1926, until studies declared that its descendants were found in Minnesota, Wisconsin and Michigan. They were described as a large, light-colored wolf but with black and white varying between individual wolves, with some all white or all black. The Native Americans of North Dakota told of how only three Great Plains wolves could bring down any sized bison.

Taxonomy

This wolf was first recorded in 1823 by the naturalist Thomas Say in his writings on Major Stephen Long's expedition to the Great Plains. Say was the first person to document the difference between a "prairie wolf" (coyote) and on the next page of his journal a wolf which he named Canis nubilus. He described one of these wolves that had been caught in a trap:

Great Plains wolf

In 1995, the American mammalogist Robert M. Nowak analyzed data on the skull morphology of wolf specimens from around the world. For North America, he proposed that there were only five subspecies of gray wolf. One of these he described as a moderate-sized wolf that was originally found from Texas to Hudson Bay and from Oregon to Newfoundland which he named C. l. nubilus. This proposal was not recognized in the taxonomic authority Mammal Species of the World (2005), which classified this wolf as one of the 27 subspecies of Canis lupus in North America.

Great Plains wolf

Lineage

Gray wolves (Canis lupus) migrated from Eurasia into North America 70,000–23,000 years ago and gave rise to at least two morphologically and genetically distinct groups. One group is represented by the extinct Beringian wolf and the other by the modern populations.

Great Plains wolf

A haplotype is a group of genes found in an organism that are inherited together from one of their parents. Mitochondrial DNA (mDNA) passes along the maternal line and can date back thousands of years. A 2005 study compared the mitochondrial DNA sequences of modern wolves from across North America with those from thirty-four specimens dated between 1856 and 1915 collected from the western United States, Mexico and the Labrador Peninsula. The historic population was found to possess twice the genetic diversity of modern wolves, which suggests that the mDNA diversity of the wolves eradicated from the western US was more than twice that of the modern population. Some haplotypes possessed by the Mexican wolf, the extinct Southern Rocky Mountain wolf and the extinct Great Plains wolf were found to form a unique "southern clade". All North American wolves group together with those from Eurasia, except for the southern clade which form a group exclusive to North America. The wide distribution area of the southern clade indicates that gene flow was extensive across the recognized limits of its subspecies.

A study published in 2018 looked at the limb morphology of modern and fossil North American wolves. The major limb bones of the dire wolf, Beringian wolf, and most modern North American gray wolves can be clearly distinguished from one another. Late Pleistocene wolves on both sides of the Laurentide Ice Sheet — Cordilleran Ice Sheet possessed shorter legs when compared with most modern wolves. The Late Pleistocene wolves from the Natural Trap Cave, Wyoming and Rancho La Brea, southern California were similar in limb morphology to the Beringian wolves of Alaska. Modern wolves in the Midwestern USA and northwestern North America possess longer legs that evolved during the Holocene, possibly driven by the loss of slower prey. However, shorter legs survived well into the Holocene after the extinction of much of the Pleistocene megafauna, including the Beringian wolf. Holocene wolves from Middle Butte Cave (dated less than 7,600 YBP) and Moonshiner Cave (dated over 3,000 YBP) in Bingham County, Idaho were similar to the Beringian wolves. The Mexican wolf (C. l. baileyi) and pre-1900 samples of the Great Plains wolf (Canis lupus nubilus) resembled the Late Pleistocene and Holocene fossil gray wolves due to their shorter legs.

Ancestor

In 2021, a mitochondrial DNA analysis of North American wolf-like canines indicates that the extinct Late Pleistocene Beringian wolf was the ancestor of the southern wolf clade, which includes the Mexican wolf and the extinct Great Plains wolf. The Mexican wolf is the most ancestral of the gray wolves that live in North America today.