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Tracey Peake, News Services, 919/515-3470

Feb. 15, 2006

NC State Paleontologist to Present Theories of Fossil Preservation at
AAAS Conference

FOR IMMEDIATE RELEASE

North Carolina State University paleontologist Dr. Mary Schweitzer will discuss her discovery of soft tissues in fossilized dinosaur bones and theories about how the preservation of such tissues is possible at the annual meeting of the American Association for the Advancement of Science (AAAS) at 10:30 a.m. CST Friday, Feb. 17 in St. Louis, Mo.

Schweitzer, an assistant professor of paleontology with a joint appointment at the N.C. Museum of Natural Sciences, will present “Dinosaurian Soft Tissue Taphonomy and Implications” as part of the symposium “New Approaches to Paleontological Investigation,” which she organized with colleague Dr. Jack Horner, a world-renowned paleontologist from the Museum of the Rockies. In her presentation, Schweitzer will outline attempts to characterize the structures she found in the bones of a 68-million-year-old Tyrannosaurus Rex and the ramifications of the discovery for future paleontological research.

In order to study the factors working to preserve the apparent tissues and cells, Schweitzer and technician Jennifer Wittmeyer repeated the demineralization technique that they used in 2005 to extract soft tissues from the original T. rex on animal bones ranging in age and variety from a nine months post-mortem ostrich bone to a 300,000-year-old woolly mammoth bone to an 80-million-year-old hadrosaur fossil. The researchers successfully retrieved similar tissues from each sample, and using a variety of methods, demonstrated the presence of apparent blood vessels, cells and soft, fibrous matrix in most of the samples studied.

“Now that we’ve seen the same structures preserved in all these different samples, we need to ask ourselves how they were preserved – what happened to essentially convert organic materials from the living state to what they are now – and if any original molecular components remain,” says Schweitzer.

She believes that heavy metals, specifically iron, may have played a role in preserving these structures. Hemoglobin, the protein inside a red blood cell, contains iron, and when this protein breaks down, the iron is released and becomes unstable. When the iron attempts to restabilize, it creates free radicals, which cause “cross linking,” or the binding together, of tissues. In living creatures, this cross linking explains why your skin loses elasticity as you age.

Once cross linking occurs in a cell or vessel, the structure usually becomes insoluble, meaning that it won’t dissolve, and may not degrade further. Schweitzer believes that heavy metal cross linking could be one mechanism by which soft tissues may be preserved within the fossils she’s studied.

“Our next steps are to figure out what’s occurring in these tissues as they fossilize, to find out what they are, chemically speaking,” says Schweitzer. “This research could lead to a new
standardized approach to fossil analysis and allow paleontologists to glean even more information from the samples they have.”

- peake -

Note to editors: AAAS symposium synopsis and presentation abstract follow.

“New Approaches to Paleontological Investigation”
Organizers: Mary Schweitzer, NC State University, Jack Horner, Museum of the Rockies
Presented: Friday, Feb. 17, 10:30 a.m. CST at the AAAS annual meeting in St. Louis
Synopsis: New, innovative, and highly sensitive technologies have recently been applied to fossil
specimens, allowing recovery of data never before possible, that has yielded new information
about long-extinct animals and the world in which they lived. This symposium highlights some
of these analytical advances, and illustrates new ways to interpret the lifestyles, relationships,
physiologies and reproductive strategies of fossil taxa. Concepts in evolution and development
(evo-devo), chemical and molecular analytical data, phylogenetics, and computer modeling will
be discussed.

“Dinosaurian Soft Tissue Taphonomy and Implications”
Author and Presenter: Mary Schweitzer, NC State University; Jennifer Wittmeyer, NC State
University (co-author)
Presented: Friday, Feb. 17 10:30 a.m. CST at the AAAS annual meeting in St. Louis
Abstract: It has long been assumed in paleontology that processes resulting in fossilization
generally progress through rapid burial, destruction of original organics, and subsequent
replacement or infilling of organic material with exogenous mineral (permineralization). The
assumption has been that no original organic material remains, and that conventional acid
demineralization techniques would result in complete dissolution of fossil remains. More
recently, forensic studies and benchtop and theoretical biochemical investigations have suggested that soft tissues and cellular remains, as well as their biomolecular constituents, degrade after death on a scale of weeks to decades, with more resistant molecules give a maximum estimate of survival of some molecular fragments between 40,000 to 100,000 years. We recently reported the presence of apparent soft tissues and cells, recovered from a well preserved Tyrannosaurus rex specimen dating to 68.5 MY before present, that suggested revision of that basic understanding. However, we have not reported analytical data derived from that material. Here, we discuss preliminary results of what will be a long term, multidisciplinary approach to the detailed analyses of these apparent biological structures. Methodologies applied to these dinosaur-derived materials include transmission electron microscopy, atomic force microscopy, electrophoretic techniques and immunochemistry. In addition we will present a methodological strategy for application to similar specimens, in order to establish a standardized approach to future fossil analyses.