Paleoecology (δ13C and δ18O stable isotopes analysis) of a mammalian assemblage from the late Pleistocene of Hidalgo, central Mexico and implications for a better understanding of environmental conditions in temperate North America (18°–36°N Lat.)

Abstract

Paleoenvironmental interpretations inferred by the isotopic ecology of mammalian assemblages from the Quaternary of Mexico are scarce. Carbon (δ13C) and oxygen (δ18O) stable isotope analysis is performed on six late Pleistocene localities from central Mexico. The objectives of the study are (1) to reconstruct the dietary traits and habitat of a mammalian community from the late Pleistocene of southeastern Hidalgo, and (2) to characterize the paleoenvironments that existed in the region, as well as placing them in the context of the paleoenvironmental conditions of temperate North America during the late Pleistocene. The carbon isotope composition shows a large diversity of dietary preferences, including C3, intermediate C3/C4, and C4 feeders; however, C3 feeders are the most abundant in the assemblage. The oxygen isotope composition also indicates a diversity of preferences for habitats, including open habitats as well as humid and closed habitats. The study reveals the presence of heterogeneous vegetation consisting of both woodland and grassland habitats during the late Pleistocene. The results obtained for the Hidalgoan assemblage fit within the paleoenvironmental pattern known for other localities in temperate North America, in particular those located in the western and central part, between the coast of California, the southern Great Plains and Texas Gulf Coast (i.e., grassland and mixed woodland/grassland habitats).