Dental microwear analysis for investigating the diet of an argali population (Ovis ammon antiqua) of mid-Pleistocene age, Caune de l’Arago cave, eastern Pyrenees, France

In recent years, dental microwear analysis has been widely used as a method for reconstructing ancient diet. The current study reconstructs the diet of Ovis ammon antiqua, a 440 000 year old argali-like sheep fossil from the Pleistocene site of the Caune de l’Arago in Southern France. The microscopic wear was observed on second upper molars with an environmental scanning electron microscope, using a magnification of ×500. Data analysis was performed on the following microwear variables: feature density, pit density, striation density, pit/striation ratio, pit size, and striation length and width. The microwear pattern of O. ammon antiqua was compared with those of extant ruminant taxa. Fossil wild sheep have significantly lower pit densities but similar scratch densities. The fossil animal shows shorter and narrower striations than extant herbivores. Our results suggest that fossil argali was a typical grazer, more so than extant ruminants. As far as diet variations are concerned, the diet of extant Caprinae varies according to season and region. In our fossil record, diet variations reflect some of the climatic changes that occurred during the Quaternary. This study shows that microwear analysis is not only a good tool for determining diet adaptations, but that it also brings indirect evidence of climatic variations.