Dental caries in the fossil record: a window to the evolution of dietary plasticity in an extinct bear

During the late Pleistocene of North America (≈36,000 to 10,000 years ago), saber-toothed cats, American lions, dire wolves, and coyotes competed for prey resources at Rancho La Brea (RLB). Despite the fact that the giant short-faced bear (Arctodus simus) was the largest land carnivoran present in the fauna, there is no evidence that it competed with these other carnivores for prey at the site. Here, for the first time, we report carious lesions preserved in specimens of A. simus, recovered from RLB. Our results suggest that the population of A. simus from RLB was more omnivorous than the highly carnivorous populations from the Northwest. This dietary variation may be a consequence of different competitive pressures.Funding for this project was provided by the ‘Spanish Ministry of Economy and Competitiveness (MINECO), grant (CGL2015-58300P) to BF, and a University of Alicante grant n° uausti15–03 to AR. FJS possess postdoctoral grant at Los Angeles County Natural History Museum (Dinosaur Institute, NHM) and the Sierra Elvira Foundation (Spain). APR is a FPI fellow of the Spanish MINECO (BES-2013-065469) associated to the project (CGL2012-37866) of BF