A Giant Bear Mandible (Agriotherium schneideri Sellards 1916) from Sedgwick County, Kansas

Abstract

In March 2017, the partial right mandible (FHSM VP-19466) of the giant Miocene-Pliocene bear, Agriotherium schneideri (Ursidae; Agriotheriinae), was recovered from the sandy sediments of an exposed paleo stream channel in northern Sedgwick County, Kansas. The mandible includes the right canine, fourth premolar, and m1-m3 molars. The vacant p1 alveolus is visible immediately behind the canine. The overall size of the mandible, measurements of the teeth, presence of a ‘chin,’ and a large premasseteric fossa confirm the specimen to be Agriotherium schneideri Sellards 1916. The worn condition of the teeth suggests that the bear was an older adult at the time of death. The relatively complete and un-abraded condition of the mandible would preclude long distance stream transport. All of the previously documented North American specimens of Agriotherium are dated from late Miocene to earliest Pliocene (∼ 10-4 Ma). Fragmentary remains attributable to Agriotherium have been previously identified from several Miocene localities in Kansas.