Cambrian–Ordovician extinction event

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Extinction intensity.svg Cambrian Ordovician Silurian Devonian Carboniferous Permian Triassic Jurassic Cretaceous Paleogene Neogene
Marine extinction intensity during the Phanerozoic eon
%
Millions of years ago
Extinction intensity.svg Cambrian Ordovician Silurian Devonian Carboniferous Permian Triassic Jurassic Cretaceous Paleogene Neogene
The blue graph shows the apparent percentage (not the absolute number) of marine animal genera becoming extinct during any given time interval. It does not represent all marine species, just those that are readily fossilized. The labels of the "Big Five" extinction events are clickable hyperlinks; see Extinction event for more details. (source and image info)

The Cambrian–Ordovician extinction event occurred approximately 488 million years ago (m.y.a.). This early Phanerozoic Eon extinction event eliminated many brachiopods and conodonts, and severely reduced the number of trilobite species.

It was preceded by the less-documented (but probably worse) End Botomian extinction event around 517 m.y.a. and the Dresbachian event about 502 m.y.a.

The Cambro–Ordovician event ended the Cambrian Period, and led into the Ordovician Period in the Paleozoic Era.

Theories[edit]

See also[edit]

Further reading[edit]

  • Gradstein, Felix, James Ogg, and Alan Smith, eds., 2004. A Geologic Time Scale 2004 (Cambridge University Press).
  • Hallam, A. and Paul B. Wignall, 1997. Mass extinctions and their aftermath (Oxford University Press).
  • Webby, Barry D. and Mary L. Droser, eds., 2004. The Great Ordovician Biodiversification Event (Columbia University Press).

References[edit]

  1. ^ Kravchinsky, V. A. (2012). Paleozoic large igneous provinces of Northern Eurasia: Correlation with mass extinction events. Global and Planetary Change, 86, 31-36.

External links[edit]