A database of South American Quaternary mammals for paleoecological analyses

Although the dynamics of Quaternary extinctions are becoming better understood on most continents, the causes and effects of these events in South America remain ambiguous. To elucidate the relative roles environmental and anthropogenic stresses played in forcing the extinctions, and to facilitate investigations of community ecological response to these changes, we are constructing a database of late-Quaternary mammalian fossil remains relating taxonomic, geographical, stratigraphic and chronological information for the South American continent.  The database will incorporate detailed geographical information and precise AMS radiocarbon dates, and is designed to coordinate with existing North American databases such as FAUNMAP/NEOTOMA and MIOMAP, and related projects in Central and South America, including ZARSUD and the Mexican Quaternary Mammals Database.  The database will be served through the U.C. Museum of Paleontology at the University of California, Berkeley, and will form the basis for analyzing occurrences of taxa through space and time via integration with web-based mapping and analytical programs.  Spatio-temporal mapping routines, combined with biostratigraphic, paleoclimatic and archaeological analyses, will allow investigations of (a) patterns of extinction relative to latitude and elevation; (b) timing of extinctions relative to those in North America and other continents; (c) relationship of extinction events with paleoclimatic variation; (d) differential attrition rates of various taxa throughout South America; (e) potential anthropogenic impacts on megafauna populations; and (f) effects of environmental changes and taxa loss on subsequent mammalian community structure.  We are currently in the process of assimilating and evaluating all published radiocarbon dates on South American mammal fossils and identifying specimens and sites requiring additional and/or corroboratory dates.  So far we have compiled information on more than 40 sites in Chile and Argentina, and preliminary analysis of 14C dates suggests an extinction event that is younger than in North America and might well have extended into the Holocene. Results of future analyses will help us understand how climate change, human actions and other factors combine to force ecosystem changes on regional and global scales, and the extent to which the late Pleistocene can be used as an analog to forecast biodiversity loss in the current era of global warming and increasing anthropogenic pressures.