Paleodiets of bovids from Makapansgat Limeworks Cave, South Africa: Based on mesowear and microwear

Paleontologists typically assume a relationship between environmental change and evolution. Such relationships are usually obscure, however, because of the difficulty in reconstructing past environments. Determination of the diet and/or habitat of taxa is one of the primary means of reconstructing past environments, and taxonomic uniformitarianism assumptions are commonly used. This method was recently tested by applying ecomorphology and stable carbon isotope analyses to seven extinct bovids from Makapansgat Limeworks Cave, a well known Plio-Pleistocene Australopithecus africanus bearing site in South Africa. Here, dental mesowear and microwear are applied to the same bovids to further refine their diet and habitat reconstructions.; With one exception, mesowear grouped the extinct taxa into the same dietary categories as stable carbon isotopes. Indeed, a close association between mesowear and stable carbon isotope results was expected since both methods are epigenetic and measure diet over an extended period of an animal's lifetime. Microwear separated an extant baseline of bovids into expected dietary categories. Extinct taxa clearly fell into two groups with the same degree of separation as the extant grazers and browsers. However, there appeared to be an "offset" in the data when compared to the extants. This offset may be due to an observer bias that excluded suspicious looking pit-like features. When a pit adjustment was applied to the fossil taxa, they all grouped into dietary categories that mirrored mesowear and isotopic results.; The five compared methods provide a temporal continuum, with genetic signals such as ecomorphology and taxonomic uniformitarianism indicating behavioral adaptations over long periods of time, stable carbon isotopes and mesowear reflecting different aspects of average diet over an animal's lifetime, and dental microwear providing dietary snapshots. This study showed that multiple epigenetic signals produce more reliable paleodietary reconstructions than genetic attributes or only one epigenetic signal. Multidisciplinary paleodietary studies, however, should include both epigenetic and genetic signals because such analyses can lead to a better understanding of the range of possible diets in lineages, the average paleodiets of taxa, and the types of habitats and paleoenvironments that organisms have inhabited through time.