Late Pleistocene paleoenvironments and megafauna from the Sierra Madre del Sur flanks and the Central Depression of Chiapas (Southern Mexico)

Pleistocene fluvial sequences have been recognised in some regions of Me ' xico as an important source of infor-mation on past environmental change using a wide range of proxies. However, this has not been attempted in Mexico's southernmost state of Chiapas until the current paper, where the main aim is to describe and date five new Late Pleistocene fossil rich sequences and to interpret their paleoenvironmental record and changes that they indicate. This interpretation is based on the sedimentology, pollen record and stable isotopes from verte-brate fossils together with the radiocarbon dating of the fluvial sediments. At Los Mangos and El Baji ' on fossil sites the fluvial sediment record reported here includes a conspicuous layer with aerodynamic Fe magnetic microspherules associated with the Younger Dryas (YD) meteorite impact which adds to the type of paleo-environments in which such meteorite impacts have been recognised. The sediment dating indicates that the fossiliferous sites are Late Pleistocene in age, and they add new locations and information for Me ' xico for this climatic phase.