Jack Sepkoski

J. John Sepkoski Jr., (July 26, 1948 - May 1, 1999), was a University of Chicago paleontologist. Sepkoski studied the fossil record and the diversity of life on Earth. Sepkoski and David Raup contributed to the knowledge of extinction events. They suggested that the extinction of dinosaurs 65 mya was part of a cycle of mass extinctions that may have occurred every 26 million years.

Early life

Sepkoski was born in Presque Isle, Maine. In 1970, Sepkoski received a B.S. degree, magna cum laude, from the University of Notre Dame, and a Ph. D. in geological sciences from Harvard University in 1977. His Ph. D. was on the field geology and paleontology of the Black Hills of South Dakota. From 1974 to 1978, Sepkoski taught at the University of Rochester. In 1978 he joined the University of Chicago and became a professor in 1986. Sepkoski was also a research associate at the Field Museum of Natural History in Chicago. He died of heart failure related to high blood pressure at the age of 50.

Sepkoski is perhaps best known for his global compendia of marine animal families and genera, data sets that continue to motivate a tremendous amount of paleobiological research. Sepkoski himself explored his compendium very thoroughly. In 1981, he famously identified three great Evolutionary Faunas in the marine animal fossil record. Each of his Evolutionary Faunas, the Cambrian, Paleozoic, and Modern Faunas, is composed of Linnean classes of animals that have covarying diversity patterns, characteristic rates of turnover, and broadly similar ecologies. Most importantly, they sequentially replaced one another as dominant groups during the Phanerozoic. Sepkoski modeled the Evolutionary Faunas using three coupled logistic functions, but the underlying drivers of the prominent shift in taxonomic composition represented by the three faunas remains unknown.

Awards

* (1983). "Charles Schuchert Award", Paleontological Society
* Elected foreign member of the Polish Academy of Sciences

elected publications

*Sepkoski, J.J., Jr. (1978). Kinematic model of Phanerozoic taxonomic diversity 1: analysis of marine orders. "Paleobiology" 4, 223–251.
*Sepkoski, J.J., Jr. (1979). Kinematic model of Phanerozoic taxonomic diversity 2: early Phanerozoic families and multiple equilibria. "Paleobiology" 5, 222–251.
*Sepkoski, J.J., Jr. (1981). A factor analytic description of the Phanerozoic marine fossil record. "Paleobiology" 7, 36–53.
*Sepkoski, J.J., Jr. (1988). Alpha, beta, or gamma: where does all the diversity go? "Paleobiology" 14, 221–234.
*Raup, D. M. & Sepkoski, J.J., Jr. (1982). Mass extinctions in the marine fossil record. "Science" 215, 1501–3.
*Raup, D. M. & Sepkoski, J.J., Jr. (Feb. 1984). Periodicity of extinctions in the geologic past. " [http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed&pubmedid=6583680 Proc Natl Acad Sci U S A.] " 81(3): 801–805.
*Sepkoski, J.J., Jr. (2002). A compendium of fossil marine animal genera. "Bulletins of American Paleontology" 364, 560 p.

External links

* Miller, Arnold. (Sep. 1999). [http://www.findarticles.com/p/articles/mi_qa3790/is_199909/ai_n8871109 Memorial: J. John Sepkoski, Jr.: A personal reflection] . "Journal of Paleontology".
* [http://neo.jpl.nasa.gov/news/news016.html NASA] , Near Earth Object Program
* [http://strata.geology.wisc.edu/jack/ Sepkoski's Online Genus Database]