Crises of the late devonian: the kellwasser and hangenberg events

Abstract

Abstract Between the Late Ordovician and the next great mass extinction in the Late Devonian the world’s marine fauna was afflicted by numerous lesser extinction events. Between them, Kaljo et al. (1996) and Walliser (1996) document over 24 bio-events in this interval. These minor extinctions are beyond the scope of this book but, by the Late Devonian the events were increasing in magnitude to such an extent that the crisis at the Frasnian-Famennian (F-F) boundary is widely regarded as one of the big five mass extinctions of the Phanerozoic. The subsequent end-Famennian or Devonian-Carboniferous (D-C) event has also been termed a mass extinction. The Devonian crises have been named by House (1985); the F-F and D-C examples were named the Kellwasser and Hangenberg events respectively, after characteristic black shale horizons in German sections. There are also grounds for considering an earlier mid-Givetian Taghanic event as a mass extinction.