Extinction event

Marine extinction intensity during Phanerozoic

Millions of years ago

(H)

K–Pg

Tr–J

P–Tr

Cap

Late D

O–S

The blue graph shows the apparent percentage (not the absolute number) of marine animal genera extinction during any given time interval. It does not represent all marine species, just those that are readily fossilized. The labels of the traditional "Big Five" extinction events and the more recently recognised Capitanian mass extinction event are clickable links. The two extinction events occurring in the Cambrian (far left) are very large in percentage magnitude, but small in absolute numbers of known taxa due to the relative scarcity of fossil-producing life at that time. (source and image info)

An extinction event (also known as a mass extinction or biotic crisis) is a widespread and rapid decrease in the biodiversity on Earth. Such an event is identified by a sharp fall in the diversity and abundance of multicellular organisms. It occurs when the rate of extinction increases with respect to the background extinction rate^[1] and the rate of speciation.

Estimates of the number of major mass extinctions in the last 540 million years range from as few as five to more than twenty. These differences stem from disagreement as to what constitutes a "major" extinction event, and the data chosen to measure past diversity.^[2]

^ Sudakow, Ivan; Myers, Corinne; Petrovskii, Sergei; Sumrall, Colin D.; Witts, James (July 2022). "Knowledge gaps and missing links in understanding mass extinctions: Can mathematical modeling help?". Physics of Life Reviews. 41: 22–57. Bibcode:2022PhLRv..41...22S. doi:10.1016/j.plrev.2022.04.001. PMID 35523056. S2CID 248215038.
^ Marshall, Charles R. (2023). "Forty years later: The status of the "Big Five" mass extinctions". Cambridge Prisms. Extinction. 1 e5. doi:10.1017/ext.2022.4. ISSN 2755-0958. PMC 11895713. PMID 40078681.

[Sudakow2022-1] Sudakow, Ivan; Myers, Corinne; Petrovskii, Sergei; Sumrall, Colin D.; Witts, James (July 2022). "Knowledge gaps and missing links in understanding mass extinctions: Can mathematical modeling help?". Physics of Life Reviews. 41: 22–57. Bibcode:2022PhLRv..41...22S. doi:10.1016/j.plrev.2022.04.001. PMID 35523056. S2CID 248215038.

[:0-2] Marshall, Charles R. (2023). "Forty years later: The status of the "Big Five" mass extinctions". Cambridge Prisms. Extinction. 1 e5. doi:10.1017/ext.2022.4. ISSN 2755-0958. PMC 11895713. PMID 40078681.

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