Dietary plasticity in ungulates: Insight from tooth microwear analysis

In recent years, tooth microwear has been used as a powerful tool for investigating mammalian diets in paleontological or archaeological contexts. Tooth microwear techniques were applied to a number of late Pleistocene assemblages of bison (Bison antiquus) from North America to analyze bison dietary traits, but more particularly, to test for dietary plasticity of the fossil species compared to their modern relatives. Modern bison species are known to be grazers from their ecology. However, the results from tooth wear analysis indicate that dietary traits were more diverse in the fossil bison than in their modern relatives. Bison paleodiets range from pure grazing to mixed feeding. The results illustrate not only the dietary plasticity for that species, but also the potential implications involved when using modern species as analogues for reconstructing the ecology of fossil species. Tooth microwear is a good proxy in archaeological contexts because it gives an insight on the diet of the last days of an animal’s life. The intra-population variability in diet is discussed in relation to the duration of formation of the assemblages (natural assemblages versus archaeological Paleo-Indian sites).