Analysis of the Masticatory Apparatus of Uintatherium anceps

CRUZ, Bob; Yale University, New Haven, CT


The Dinocerata is an extinct order of specialized herbivorous mammals who range from the Paleocene to the mid-Eocene of the Cenozoic. Migrating from Asia, they populated the North America Rocky Mountain region after the KPg extinction to become the largest land mammals of their time. They were also the first mammals to evolve distinctive head ornamentation, with 3 pairs of bony skull protuberances occurring in the earliest lines and large prominent bony skull knobs in the last members of the order. Both males and females had large saber-like incisors, with premolars and molars that tightly occluded (unlike any later herbivorous mammals). This research examines the jaw musculature and the dentition of the most commonly-occurring specimen, Uintatherium anceps of the early Eocene in order to evaluate feeding habits as well as consider possible reasons for extinction.