Was the Giant Short-Faced Bear a Hyper-Scavenger? A New Approach to the Dietary Study of Ursids Using Dental Microwear Textures

摘要: Dramatic environmental changes associated with global cooling since the late Miocene, and onset of glacial-interglacial cycles in Pleistocene served as a backdrop to evolutionary radiation modern bears (family Ursidae). These likely prompted food availability, triggered dietary adaptations that motive forces ursid evolution. Here, we assess correspondence dental microwear textures first second lower molars diet extant ursids. We use resulting baseline data evaluate hypothesis giant short-faced bear, Arctodus simus, was bone consumer hyper-scavenger at Rancho La Brea, California, USA. Significant variation along tooth row is consistent functional differentiation, molar serving better recorder than first. Results evince significant among species: carnivorous omnivorous ursids (Ursus maritimus, U. americanus) have significantly higher more variable complexity (Asfc) herbivorous ones (Ailuropoda melanoleuca, Tremarctos ornatus, malayanus), A. melanoleuca differentiated from maritimus americanus by anisotropy (epLsar) values. simus Brea exhibits wear attributes most comparable its closest living relative (T. ornatus), which inconsistent hard-object (e.g., bone) consumption, were consuming hyper-scavengers across their range.