Trained as a stratigrapher and paleontologist at Harvard (Ph.D., 1977), Jack Sepkoski accepted his first academic appointment at the University of Rochester while he was still working on his degree. In 1978, he and David Raup were lured away to the University of Chicago, where they rapidly helped establish that school as the center of the new quantitative paleobiology. Sepkoski is best known for his quantitative analyses of the history and diversity of life and his efforts to define the shape of evolutionary expansion and extinction. His discovery of a statistically significant periodicity of mass extinction events was enormously influential, and helped facilitate acceptance of theories of the extraterrestrial origins of mass extinction. Sepkoski died of a heart attack at age 50 on May 1, 1999.
From the guide to the J. John Sepkoski Papers, 1969-1999, (American Philosophical Society)
