Texas wolf

The Texas wolf (Canis lupus monstrabilis) is an extinct subspecies of gray wolf, distinct from the Texas red wolf (Canis rufus), whose range once included southern and western Texas and northeastern Mexico.

Description
It was darker than its more northern cousins, and has a highly arched frontal bone.

Taxonomy
It is recognized as a subspecies of Canis lupus in the taxonomic authority Mammal Species of the World (2005).