Stratigraphy

Mass extinction events read from the rock and fossil record: Permian-Triassic Extinction Event, Cretaceous-Paleogene Extinction Event, Late Ordovician Mass Extinction, Late Devonian Extinction and Triassic-Jurassic Extinction Event, the so-called Big Five. Belongs here: a mass extinction event whose primary evidence is the stratigraphic and fossil record. Does not belong here: the impact or volcanic event sometimes proposed as an extinction's cause, held under Geochronology or Volcanology where that is the phenomenon's own primary identity, such as the Chicxulub Impact.