Biotic selectivity during the K/T and Late Ordovician extinction events
Date of Original Version
The differing environmental effects of a glaciation and an impact event are reflected in significantly differing ecologic responses during the Late Ordovician and Cretaceous/Tertiary (K/T) mass extinctions. During the Late Ordovician glaciation most biotic changes were associated with an intensifying climatic gradient and glacioeustatic sea-level changes. During the K/T event most biotic changes were related to a short-term loss of primary productivity, consistent with a loss of sunlight and other ancillary effects of an impact. Animals in food chains that required a supply of food derived from photosynthesis suffered the greatest extinction during the K/T event. Many K/T survivors may have been buffered from the loss of primary productivity by feeding on detritus or being starvation resistant. The marked differences in ecological patterns between the two events affirms a fundamental difference in the mechanisms of extinction.
Publication Title, e.g., Journal
Special Paper of the Geological Society of America
Sheehan, Peter M., Patricia J. Coorough, and David E. Fastovsky. "Biotic selectivity during the K/T and Late Ordovician extinction events." Special Paper of the Geological Society of America 307, (1996). doi: 10.1130/0-8137-2307-8.477.