Sunday, 5 October 2008: 9:15 AM
George R. Brown Convention Center, General Assembly Theater Hall B
The Late Ordovician witnessed the second-most devastating collapse of the biosphere, including the extinction of an estimated 57% of marine genera, and triggering significant reorganization among the major clades of the Paleozoic Evolutionary Fauna. This ancient event provides relevant context to the modern biotic crisis because of its similar global climate regime involving major continental glaciers centered on the South Pole. The nearly continuous, 1.1 km thick stratigraphic section on Anticosti Island (Quebec) records the Rawtheyan–Telychian time interval and provides a unique opportunity to understand the extinction and origination dynamics of shallow-water subtropical organisms through the Ordovician biotic crisis because the fauna, phylogeny, sedimentary facies, biogeography, and paleocommunities can be very well constrained. The collection and systematic paleontology of the Anticosti fauna has reached a high level of maturity in most clades, and the vast majority of all known specimens and all modern studies can be keyed into a single locality system containing more than 1,500 localities with precise geographic and stratigraphic data. These data will be pooled into a single compendium that can examine the distribution of single taxa or communities temporally, on onshore-offshore gradients, and most importantly through the end-Ordovician biosphere collapse and early recovery through the Telychian.