AGRIOTHERIUM SCHNEIDERI FROM THE HEMPHILLIAN OF CENTRAL MEXICO

A well-preserved upper and lower dentition of Agriotherium schneideri from the late Tertiary of Guanajuato, Mexico, permits a better underst anding of this poorly known bear. Other North American species have be en assigned to this genus, but only A. schneideri is here considered v alid. Despite scant material, it appears that this ursid displayed a w ide range of variability in its dentition. Paucity of specimens indica tes that Agriotherium and its contemporary, Indarctos, were less commo n in the New World than in the Old World. True carnassials and massive , potentially bone-crushing cheekteeth imply that both genera were act ive predator-scavengers rather than more passive omnivores with a most ly herbivorous diet. The brief geologic time range of Agriotherium in North America makes it a useful biochronologic marker, albeit on a lim ited basis due to scarcity of specimens.