Public Release:  Paleontological data better than expected

Researchers study possible bias in the fossil record

Virginia Tech

Blacksburg, Va., Oct. 25, 2002 -- The quality and completeness of the fossil record and its credibility as a source of information about the history of life have been debated since before Charles Darwin's time. Now, as part of the Paleobiology Database project, a systematic examination is being conducted with some good news so far.

At the Geological Society of America's 114th annual meeting in Denver Oct. 27-30, Virginia Tech professor of geological sciences Michael Kowalewski will present findings regarding sturdy and fragile marine fossils.

"Not all fossils are created equal," Kowalewski says. "Some are sturdy. They have thick shells or skeletons. Some are fragile, with thinner shells or skeletons. So we would expect to find more records of organisms with tough skeletons."

But a preliminary study of the Paleobiology Database has revealed that fragile fossils occur as frequently as durable fossils.

"That's good news. It means that this intuitively obvious bias is not as severe as we expected, and the fossil record may be a more reliable source of information than we believed" Kowalewski says. "In this project, we are not trying to reconstruct the evolutionary history of biodiversity or assess the magnitude of mass extinctions, but to evaluate whether the fossil record can indeed provide reliable data for such studies," he emphasizes.

The Paleobiology Database is a collective effort, by nearly 100 faculty members and students from various institutions, to create a central, accessible database. "It is the largest effort within the paleontology community to integrate scientific information accessible in the fossil record," says Kowalewski.

Kowalewski's group is one of several working groups that deal with specific issues. "Our group is evaluating the quality of the fossil record -- how credible, reliable, accurate, precise, and complete is the physical record. How well are fossils preserved? What information has been lost? What information preserved? What information can be extracted? We are also mining previous literature to obtain qualitative and quantitative data suitable for addressing these questions. We are also contributing our own data collected in our individual field projects," he says.

"The fossil record can yield data that can be used to address a variety of questions regarding issues such as changes in diversity or severity of mass extinctions. By assessing the quality of those data, our project can provide guidelines for enhancing studies that deal with those fundamental questions regarding the history of life on the earth.

Kowalewski will present the paper, "Phanerozoic taphonomy of marine benthos: Effects of skeletal durability on macroevolutionary trends," on Wednesday, Oct. 30, at 4:15 p.m. in Colorado Convention Center room A102/104/106 Co-authors are Anna Behrensmeyer of the Smithsonian Institute, Franz Fursich of the University of Würzburg, Robert Gastaldo of Colby College, Susan Kidwell and Matthew Kosnik of the University of Chicago, Roy Plotnick of the University of Illinois, Chicago, Raymond Rogers of Macalester College, and John Alroy of the National Center for Ecological Analysis and Synthesis.

The database is located at the National Center for Ecological Analysis and Synthesis at the University of California, Santa Barbara. The project is funded by the National Science Foundation.

The presentation is part of the day-long symposium on Seafood Through Time--The Ecologic Context of the History of Life, honoring retired Virginia Tech geological sciences professor Richard Bambach.

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