Paleodietary reconstruction of fossil horses from the Eocene through Pleistocene of North America

摘要: Paleodietary trends for North American horses from Hyracotherium (early Eocene) through Equus (late Pleistocene) were examined using dental microwear analysis. Over 1200 fossil specimens analyzed enamel and results compared to an extensive database of extant ungulates. This study tests the hypothesis that Eocene browsed on low abrasion foods whereas Oligocene later had more abrasive diets concomitant with spread open habitats examines correlation between acquisition hypsodonty beginning grazing. Microwear indicate early middle species engaged mostly in fruit browsing. In contrast, late taxa have scratch numbers typical grazing mixed-feeding ungulates, but very fine textures which are unusual modern C4 grazers consumption relatively grasses. An increase overall dietary is evident Miocene members Anchitherinae (sensu stricto) leaf browsing while other forms committed or alternating grass leaves. (ss) continue rely leaves until they became extinct Miocene, Equinae either mixed feeding Pleistocene. Dietary increased further continued Most Pleistocene not rather even Increased pitting coarser Plio–Pleistocene reinforces idea may be due grit encroachment food items and/or a shift toward grasses than steady amount consumed.