A well-preserved upper and lower dentition of Agriotherium schneideri from the late Tertiary of Guanajuato, Mexico, permits a better understanding of this poorly known bear. Other North American species have been assigned to this genus, but only A. schneideri is here considered valid. Despite scant material, it appears that this ursid displayed a wide range of variability in its dentition. Paucity of specimens indicates that Agriotherium and its contemporary, Indarctos, were less common in the New World than in the Old World. True carnassials and massive, potentially bone-crushing cheekteeth imply that both genera were active predator-scavengers rather than more passive omnivores with a mostly herbivorous diet. The brief geologic time range of Agriotherium in North America makes it a useful biochronologic marker, albeit on a limited basis due to scarcity of specimens.

Author notes

Associate Editor was Karen McBee.