DENTAL MICROWEAR TEXTURE COMPARISONS OF EXTINCT CARNIVORANS TO EXTANT SOCIAL HYPERCARNIVORES, SOLITARY CARNIVORES, AND SOLITARY HYPOCARNIVORES

Within Carnivora, a small number of extant species (~13%) exhibit some degree of sociality including group feeding. However, there are few methods of evaluating carnivoran social behavior from the fossil record. One potential test is dental microwear texture analysis (DMTA), a 3D method for quantifying tooth surface texture to assess relative hard object (e.g., bone) and tough object (e.g., soft tissue) consumption within the last few days of life. We performed a meta-analysis of all published carnivoran DMTA data to see if values between social and solitary species were distinct enough to compare to fossil values. While there may be phylogenetic factors constraining the evolution of dental structures and thus feeding strategies, we binned each species into a behavioral group: social hypercarnivores (four species, n = 119), solitary carnivores (three species, n = 78), and solitary hypocarnivores (four omnivorous bear species, n = 43). We found that solitary carnivores consume significantly more hard and tough objects than social hypercarnivores (p = 0.01 and 0.03). Solitary hypocarnivores consume more hard objects than solitary carnivores (p = 0.01) and more tough objects than social hypercarnivores (p = 0.04). These results suggest more dietary plasticity and greater carcass utilization within both solitary groups. We then compared these three groups to four extinct species: a suspected solitary hypercarnivore (Panthera atrox, n = 15), a suspected social hypercarnivore (Canis dirus, n = 18), a debated solitary hypercarnivore (Smilodon fatalis, n = 15), and a debated solitary omnivore (Arctodus simus, n = 16). P. atrox tough object consumption was most similar to solitary hypercarnivores, but hard object consumption was much lower than any group. C. dirus and S. fatalis are not significantly different from social hypercarnivores nor solitary hypocarnivores, but their values are closer to the social group. A. simus could not be distinguished from any group, with values the most similar to social hypercarnivores, suggesting that omnivory may confound this type of analysis. One result of our fossil analysis is that there may be feeding types either not seen in modern species, or not represented in the modern dataset, and expanding our dataset to include more modern feeding types may help clarify future analyses.