Is Carnivoran Skull Morphology Dependent on Predatory Style?

Living carnivorans are diverse both in skull morphologies and in feeding style. Because predation as a feeding style is highly reliant on vision, we wished to determine if carnivoran skull morphology—particularly the morphology of the orbit—were related to feeding style. We photographed the skulls of museum specimens of 48 extant carnivore species ( n = 225) and three Eocene‐age carnivorans ( n = 7). From this sample, we measured the relative size and completeness of the orbit as well as the relative proportions of the face, orbital region, and cranium. We compared these measurements with taxonomic affinity, diel activity pattern, and feeding style of these species. The longest orbital rims were found among the felids and the grey seal. The felids and phocids also had orbits with the largest relative diameter (measured from the postorbital process–dacryon). Diurnal hunters and more omnivorous species such as ursids and herpestids tended to have smaller orbital diameters. Nocturnal hunters such as felids and genets had the shortest faces and longest crania overall, in contrast to Canis and Ursus , which had the longest faces but shortest crania. Herpestids, hyaenids, and mustelids were intermediate in these proportions. Using these baseline data on Eocene carnivorans, we found that the small canid Hesperocyon overlapped with both canids and herpestids, while the Eocene felids Hoplophoneus and Dinictis demonstrated early establishment of the typical “cat‐like” skull proportions and feeding behaviors.