Morphometric variation in the cranium, mandible, and dentition of Canis latrans and Canis lepophagus (Carnivora: Canidae) and its implications for the identification of isolated fossil specimens

Morphometric variation in the cranium, mandible, and dentition of the Blancan coyote, Canis lepophagus, and the modern coyote, Canis latrans, was evaluated using discriminant function analysis to determine if continuous characters can be used to differentiate these 2 taxa. Measurements from 88 continuous characters were partitioned into 4 groups (cranial, upper dentition, mandibular, and lower dentition) and analyzed separately to evaluate whether isolated or fragmentary specimens support species-level discrimination. Measurements from the most complete, Irvingtonian-aged coyote skull were added to the analyses as an unknown to assess the morphometric affinity of this fossil specimen. Results indicate that complete morphometric separation is possible between C. lepophagus and C. latrans, but only using cranial or mandibular data. This separation is maintained for crania when the number of analyzed measurements is reduced to as little as 1 (height of the braincase). In contrast, a suite of mandibular measurements is needed to establish non-overlapping morphometric separation. The Irvingtonian-aged skull consistently groups with C. latrans, supporting the presence of the modern coyote in the Irvingtonian.