ASSESSING DIETARY VARIATION OF EXTINCT AND EXTANT PECCARIES IN THE AMERICAS THROUGH STABLE ISOTOPES AND DENTAL MICROWEAR TEXTURE ANALYSIS

Glacial and interglacial periods of the Pleistocene document rapid climate fluctuations, forcing some species to adjust their diets in response to alterations in vegetation. For example, geochemical analyses have demonstrated that peccaries, such as Platygonus, increased the proportion of C₄ vegetation they consumed with interglacial warming. Further, both modern and extinct members of the clade Tayassuidae are known to heavily influence landscape composition through seed dispersal and seed predation; however, little is know about how their diets vary over both space and time. Dental microwear texture analysis (DMTA), the three-dimensional analysis of microscopic wear features resulting from food processing, provides information on the last few days to weeks of an animal’s diet and can help clarify if both modern and fossil peccaries had diets with similar textural properties. Oxygen and carbon isotopes from tooth enamel can instead provide information on relative aridity/climate and forest density/diet, respectively. When coupled, these techniques can provide a more complete picture of tayassuid paleoecology. Through DMTA and isotopic analyses, we test the hypothesis that Mylohyus consumed harder food items than Platygonus during the Pleistocene, consistent with morphological interpretations. Further, we compare diets of these extinct peccaries to the extant white-lipped (Tayassu pecari) and collared (Pecari tajacu) peccaries to assess dietary variation in both the modern and fossil taxa. Dental microwear texture analysis reveals larger differences between living and extinct species, than analyses between the two species of extant peccaries or Pleistocene peccaries. Geochemical data instead reveal the degree of overlap in the isotopic composition of food consumed.