Up is down: testing the equivalence in dental wear patterns of the upper and lower carnassial

The analysis of dental microwear is widely applied to reconstruct the diet of different fossil species. Dental microwear is usually sampled on worn facet, that are produced during the food processing. To maximize the sample size, tooth-wear are sampled on upper and lower teeth assuming equality in wear patterns between two homologous opposite facets. Anyhow, previous research on fossil herbivores have highlighted potential discrepancies between upper and lower teeth, particularly in non-homologous facets, raising questions about the validity of this practice. Here we test if wear of the homologous facets of the slicing portion of the carnassials in four species of extant carnivores can be analyzed without distinction, resulting in the same ecological evidence. To achieve a high-resolution representation of these patterns, we used Dental Microwear Texture Analysis. The results of similarity tests validate that there is no statistically significative difference between SSFA attributes and, moreover, their equivalence. This statistic equivalence opens new possibilities for the future doubling the data availability, at least for extant and fossil carnivores, to overcome the scarcity of the fossil record.