Evolution and Extinction Rate Controls

abundance ammonoids animal communities Appohimchi Subprovince Ashgill beds Benthic Assemblage benthos Berry and Boucot biogeographic biogeographic units bivalves boundary brachial valve brachiopods cladogenetic cladogenetic evolution climatic Complex of Communities conclusions correlation cosmopolitan taxa distribution dolomite Early Devonian Eastern Americas Realm Eifel endemic environmental Eocoelia eurypterids evaporitic evolving extinction event extinction rate factors faunas Frasne Gedinne genera genus Givet graptolites groups high-diversity hypersaline indicates interbreeding populations interval Late Llandovery Late Ordovician Late Silurian level-bottom communities Limestone Llandovery low-diversity Malvinokaffric Realm marine Middle Devonian munities North Silurian Realm number of communities number of taxa occur Old World Realm organisms Paleozoic pedicle valve Phanerozoic phyletic evolution platforms possible present Pridoli provincialism quiet-water rate of evolution reef environments region regression relatively rough-water shallow-water shells Silurian Silurian and Devonian Silurian-Devonian species taxic diversity taxon taxonomic diversity terminal extinction tion total number typical examples Virgiana Wenlock widespread worldwide Zone