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.

Awards

• (1983). Charles Schuchert Award, Paleontological Society

Selected publications

• Raup, D. M. & Sepkoski, J.J., Jr. (1982) Science. 215, 1501–3.
• Raup, D. M. & Sepkoski, J.J., Jr. (Feb. 1984). Periodicity of extinctions in the geologic past. Proc Natl Acad Sci U S A., 81(3): 801–805.

External links

• Miller, Arnold. (Sep. 1999). Memorial: J. John Sepkoski, Jr.: A personal reflection. Journal of Paleontology.
• NASA, Near Earth Object Program