The Mexican wolf (Canis lupus baileyi), also known as the lobo, is a subspecies of gray wolf once native to southeastern Arizona, southern New Mexico, western Texas and northern Mexico. It is the smallest of North America's gray wolves, and is similar to C. l. nubilus, though it is distinguished by its smaller, narrower skull and its darker pelt, which is yellowish-gray and heavily clouded with black over the back and tail. Its ancestors were likely the first gray wolves to enter North America after the extinction of the Beringian wolf, as indicated by its southern range and basal physical and genetic characteristics.