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May 4, 1999
For immediate release
Contact: Steve Koppes
 	(773) 702-8366

Paleontologist J. John Sepkoski Jr., 1948-1999

University of Chicago paleontologist J. John Sepkoski Jr., whose work has had innovative and far-reaching impact on the scientific understanding of the fossil record and the diversification of animal life throughout much of Earth's history, died Saturday, May 1, of sudden heart failure related to high blood pressure. He was 50.

"Paleobiology is a small profession, so when we lose one of our very greatest, it's really a tremedously painful experience," said Harvard University paleontologist Stephen Jay Gould, with whom Sepkoski studied as a graduate student. "Jack was one of the leading lights of the profession."

One of Sepkoski's major contributions was quantifying the nature of life's diversity through time, said Douglas Erwin, a research paleontologist at the Smithsonian Institution in Washington, D.C., and editor of the journal Paleobiology. "He exhaustively documented the ups and downs of life through the last 600 million years. By collecting the data and developing a series of statistical methods to study it, he gave us a new way of understanding the history of life in the oceans.."

During the 1980s and 1990s, there were many meetings of paleontologists during which literally every speaker used a figure from Sepkoski's work, Erwin said. "His contributions were fundamental to everything that people were doing," he said.

Sepkoski's death was a huge loss for paleontology, said University of Chicago paleontologist David Jablonski. "Jack was extremely generous with his ideas and for that matter with the huge database that he spent decades compiling. His combined approach of mathematical modelling, paleoecology and massive data arrays really changed the way we do paleontology," Jablonski said.

His work is discussed in the book Mystery of Mysteries: Is Evolution a Social Construction? by Michael Ruse, published this year by Harvard University Press. "One of the first chapters is on Charles Darwin and one of the last chapters is on Jack," Jablonski said.

During the 1980s, using rigorous statistical analyses of the fossil record, Sepkoski and his Chicago colleague David Raup put forth the controversial theory that catastrophic extinctions of marine animals may have occurred approximately every 26 million years during the past 250 million years of Earth's history. These periodic events also included the extinction of the dinosaurs 65 million years ago. The extinctions previously were thought to have been random events.

The theory helped open the possibility that mass extinctions both on land and in the oceans were caused by some force external to Earth, such as catastrophic comet and asteroid impacts of the type that inspired the films "Deep Impact" and "Armageddon" and inspired the popular Shriekback song "Nemesis." These findings prompted a major interdisciplinry research effort on extinction events in the fossil record.

The exact cause of periodic extinctions remains a mystery. "The theory has been under attack, but I don't hink anyone's been able to disprove it," said Sepkoski's wife, Christine M. Janis, a Brown University paleontologist.

Sepkoski's taste in music was as unconventional as some of his scientific theories. His favorite musical group was the punk rock Sex Pistols. "He thought that the Velvet Underground album was the best album of all time," Janis said.

Sepkoski was born July 26, 1948, in Presque Isle, Maine. "He started collecting dinosaur bones and fossils in New Jersey when he was 10 and had wanted to become a paleontologist since that time," said his former wife, Maureen Meter.

He earned his B.S. degree, magna cum laude, from the University of Notre Dame in 1970 and his Ph.D. in geological sciences from Harvard University in 1977. His Ph.D. research was on the field geology and paleontology of South Dakota's Black Hills.

He taught at the University of Rochester from 1974 to 1978 first as an instructor, then as an assistant professor. He was appointed Assistant Professor in the Department of Geophysical Sciences at the University of Chicago in 1978. Sepkoski attained the rank of Associate Professor in 1982 and Professor in 1986. He also had been a research associate at the Field Museum of Natural History in Chicago since 1980.

Sepkoski held visiting professorships at the California Institute of Technology in 1986 and at Harvard Uniersity in 1990 and 1991. In 1988, Sepkoski visited the University of California at Los Angeles as a senior fellow and lectured at the Polish Academy of Sciences, where he was elected a foreign member.

The Paleontological Society bestowed its Charles Schuchert Award upon Sepkoski in 1983. He served a term as the society's president from 1995 to 1996 and founded the Paleontological Society International Research Program, or PalSIRP, the society's program for assisting paleontologists in the countires of the former Soviet Union through small competitive grants.

He was co-editor of the journal Paleobiology, regarded as the major journal of his field, from 1983 to 1986 and a member of its editorial board from 1987 to 1989.

"Jack was admired by his family, friends and colleagues not only for the brilliance of his research, but also for his untiring devotion to scholarship and teaching," said Mike Foote, a University of Chicago paleontologist. He taught popular, large-enrollment courses in the University's Core curriculum, advanced undergradaute courses in paleontology, and demanding, advanced graduate courses. He took great satisfaction in mentoring and advising students and colleagues, as well, Foote said.

When Sepkoski led paleontological field trips for undergraduate and graduate students over the years, his son, David, was a frequent companion. David Sepkoski went on to receive an M.A. degree from the University of Chicago and is a doctoral student in the history of science at the University of Minnesota.

He is survived by his wife, Christine M. Janis of Providence, R.I.; his son, David Sepkoski of Minneapolis, Minn.; his father, Joseph J. Sepkoski of Sparta, N.J.; two sisters, Carol Sepkoski of Cambridge, Mass., and Diane Karl of Cedar Brook, N.J.; and his former wife, Maureen Meter of Chicago. Sepkoski also had a dog, Ronnie.

Arrangements for a memorial service are pending. In lieu of flowers, donations may be made to PalSIRP, c/o Dr. Thomas W. Kammer, Treasurer, Paleontological Society, Dept. of Geology and Geography, West Virginia University, P.O. Box 6300, Morgantown, WV 26506-6300.

Radio stations: The University of Chicago has an ISDN line. Please call for information. For more news from the University of Chicago, visit our Web site at

Steve Koppes
University of Chicago News Office
5801 South Ellis Ave. Room 200
Chicago, IL 60637-1473
773-702-8324 (fax)

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