List of extinction events

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An extinction event is a relatively fast drop in the number of species living on Earth. It occurs when the rate of extinction increases more than the rate of speciation. This is a list of the largest. Major extinction events are important to both geology and evolution.[1][2][3]

The Phanerozoic[change | change source]

Marine extinction intensity through time. 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.

There are five major extinction events in the Phanerozoic eon, and many smaller events.[3] In order of time, latest first:

1. K/T extinction event. The Cretaceous/Tertiary extinction event ended the Mesozoic era and started the Cainozoic era.[4]

2. End–Triassic extinction event.[5][6]

3. P/Tr extinction event. The Permian/Triassic extinction event ended the Palaeozoic era and started the Mesozoic era.[7][8]

4. Late Devonian extinctions, at the Frasnian/Famennian junction.[9]

5. End–Ordovician extinction event. After a series of lesser events, the end-Ordovician extinction resulted in an estimated 84% species loss.[10]

Lesser Phanerozoic extinctions[change | change source]

Other extinction events in the Phanerozoic also had significant impact on the evolution of the biota.

  1. EoceneOligocene transition. From the middle of the Eocene to early in the Oligocene there were a number of events. The climate became much cooler, ice formed on Antarctica, and there was a turnover in aquatic and terrestrial groups.[11]
  2. Vendian/Cambrian extinction event. Extinctions have been claimed for three groups: the acritarchs, trace fossils, and the famous Ediacaran fossils. Not much is known about this event.

References[change | change source]

  1. Huggett, Richard J. 1997. Catastrophism. new ed. Verso.
  2. Elewa A.M.T. (ed) 2008. Mass extinctions. Springer, Berlin.
  3. 3.0 3.1 Hallam A. and Wignall P.B. 1997. Mass extinctions and their aftermath. Oxford.
  4. MacLeod N.; et al. (1997). "The Cretaceous–Tertiary biotic transition". Journal of the Geological Society. 154 (2): 265–292. doi:10.1144/gsjgs.154.2.0265.
  5. Benton M.J. 1991. What really happened in the Late Triassic? Historical biology 5, 263–278.
  6. Benton M.J. 1995. Diversification and extinction in the history of life. Science 268, 52–58.
  7. Benton M.J. 2005. When life nearly died: the greatest mass extinction of all time. Thames & Hudson, London. isbn=978-0500285732
  8. Erwin DH 1993. The great Paleozoic crisis; life and death in the Permian Columbia, N.Y. isbn=0231074670
  9. McGhee, George R. Jr 1996. The Late Devonian mass extinction: the Frasnian/Famennian crisis. Columbia, N.Y. ISBN 0231075049
  10. Jablonski D. 1994. Extinctions in the fossil record. Phil Trans Roy Soc B344, 11–17.
  11. Prothero, Donald 1994. The Eocene–Oligocene transition: paradise lost. Columbia University Press, New York. ISBN 0-231-08091-3