DISTINGUISHING DIRE WOLVES FROM OTHER CANIDS BASED ON MORPHOLOGY

The dire wolf was a large wolf-like canid that occurred across North America and into South America during the late Pleistocene. Described as Canis dirus in 1858, this canid is generally considered to be more robust than the grey wolf (Canis lupus), with a larger skull, broader shoulders, and massive pelvis. Distinguishing dire wolf characters include broad palate and frontal regions, high sagittal crest with a backwards extension that exceeds other wolves, large upper and lower carnassials, reduced P⁴ deuterocone and M¹ hypocone, and both the P² and P₂ often lack posterior cusps. Morphological characters used to identify the dire wolf have generally focused at the species level with comparison to the congeneric C. lupus. However, classification of the dire wolf as Canis has not always been supported, with Merriam placing it as a distinct genus, Aenocyon, in 1918. Subsequent taxonomic identifications synonymized Aenocyon dirus as Canis dirus until recently, when genetic studies indicated dire wolf is a divergent lineage and falls outside the genus Canis, thereby the genus Aenocyon was resurrected for the dire wolf. This project reviews past criteria for separating dire wolf from grey wolf and plans to incorporate micro-CT technology on canid crania, particularly of the auditory region, to further investigate the phylogenetic relationships of these canids based on morphology.