Paleoecology of the Cretaceous-Tertiary mass extinction in planktonic foraminifera

摘要: Abstract Paleobiogeographic patterns of the Cretaceous–Tertiary (K–T) mass extinction in planktonic foraminifera Tunisia, spanning environments from open marine upper bathyal, to shelf and shallow marginal settings, indicate a surprisingly selective environmentally mediated extinction. This selectivity is apparent all environmental proxies used evaluate extinction, including species richness, ecological generalists, specialists, surface subsurface dwellers, whether based on number or relative percent abundances species. The following conclusions can be reached for deep environments: about three quarters disappeared at near K–T boundary only generalists able tolerate wide variations temperature, nutrients, salinity oxygen survived. Among (heterohelicids, guembelitrids, hedbergellids globigerinellids), dwellers Ecological which largely consisted two morphogroups opportunistic biserial triserial also suffered selectively. Biserials thrived during latest Maastrichtian well stratified settings dramatically declined early Danian. Triserials environments, similarly stressed ecosystems, Maastrichtian, but dominated both restricted highly pattern reflects dramatic changes salinity, nutrients across low latitude Tethys ocean appear result long-term (e.g., climate, sea level, volcanism) short-term effects (bolide impact).