Carbon-isotope composition of artiodactyl tooth enamel and its implications for paleodiets

作者：Bian Wang, Catherine Badgley · 发表于：Frontiers in Ecology and Evolution · 年份：2022 · DOI：10.3389/fevo.2022.958859 · 被引用次数：8 · 研究领域：Evolution and Paleontology Studies、Isotope Analysis in Ecology、Wildlife Ecology and Conservation

The stable carbon-isotope composition of mammalian tooth enamel is a powerful tool for reconstructing paleodiet and paleoenvironment. Its application in the fossil record relies on a thorough understanding of the isotopic composition of mammalian diets in modern ecosystems. We compiled and evaluated a global dataset of the carbon-isotope values of artiodactyl tooth enamel, supplemented by new samples, for 79 extant species. After correcting for differences in atmospheric carbon-isotope composition, body mass, and digestive physiology, we compared the inferred carbon-isotope values of ingested forage (δ 13 C diet ) among seven feeding categories. The artiodactyl herbivore dietary spectrum is expressed through a wide range of δ 13 C diet values, with the most depleted mean value in frugivores and the most enriched in obligate grazers. In general, grazing species have a broader range of isotope values than browsing species, suggesting a wider dietary niche breadth. Notably, variable grazers exhibit a bimodal distribution of δ 13 C diet values, with North American and Asian taxa consuming C 3 diets and African taxa consuming C 4 diets, reflecting the amount of C 4 vegetation in the environment. Variation in δ 13 C diet values also occurs among terrestrial ecoregions and artiodactyl clades. Grassland ecoregions differ significantly from forest ecoregions. We detected a low but significant phylogenetic signal in the mean δ 13 C diet values of extant species, with some of the oldest...