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Periodic Extinction of Families and Genera
David M. Raup and J. John Sepkoski
New Series, Vol. 231, No. 4740 (Feb. 21, 1986), pp. 833-836
Published by: American Association for the Advancement of Science
Stable URL: http://www.jstor.org/stable/1696675
Page Count: 4
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Eight major episodes of biological extinction of marine families over the past 250 million years stand significantly above local background (P < 0.05). These events are more pronounced when analyzed at the level of genus, and generic data exhibit additional apparent extinction events in the Aptian (Cretaceous) and Pliocene (Tertiary) Stages. Time-series analysis of these records strongly suggests a 26-million-year periodicity. This conclusion is robust even when adjusted for simultaneous testing of many trial periods. When the time series is limited to the four best-dated events (Cenomanian, Maestrichtian, upper Eocene, and middle Miocene), the hypothesis of randomness is also rejected for the 26-million-year period (P < 0.0002).
Science © 1986 American Association for the Advancement of Science