View article

Patterns of morphological variation in the skulls of extant bears were studied as they relate to diet and feeding behaviour. Measurements of craniodental features were used to compute indices that reflect dietary adaptations of the dentition and biomechanical properties of the skull, jaw and related musculature. Species were classified as either carnivores, omnivores, herbivores or insectivores. Differences among dietary groups were assessed with analysis of variance and discriminant factor analysis. Results demonstrated significant morphological separation among all four groups. Carnivores were distinguished by, among other features, molar size reduction, flexible mandibles and, most surprisingly, relatively small carnassial blades. In contrast, herbivores displayed, among other features, large molar grinding areas, rigid mandibles and large carnassial blades. The insectivorous sloth bear was characterized by …