The major researcher here is
Mary Schweitzer, who has been involved in this kind of work now for over ten years. She hit the news in 1997 with a possible detection of heme compounds as remains from dinosaur hemoglobin (
Heme compounds in dinosaur trabecular bone, M. Schweitzer et al; PNAS Vol. 94, Jun 1997, pp. 6291-6296) and this was widely and erroneously reported as a find of blood cells and/or complete hemoglobin molecules. There was also an earlier report of possible dinosaur DNA, but that did not pan out. It was almost certainly contamination. She has definitely found some of the more durable proteins (like keratin). The work is fascinating, and she focuses on cases of exceptionally good preservation.
These are highly degraded remains at the molecular level, which have not been fully mineralized and so traces of organic compounds may even remain.
An interesting detail; Schweitzer is a Christian; and she gets very angry at the way her work is used by creationists. Unfortunately, she has not spoken up about this clearly in public. I emailed her some years ago to ask about the heme compounds research, and she expressed a very strong reaction against the creationist misrepresentations on the "blood cells" issue mentioned above. There is no serious question about the age of the fossils.
This particular report is a new one, and it is reported in
Science, March 25 2005. The formal reference to the scientific paper is:
Soft-Tissue Vessels and Cellular Preservation in Tyrannosaurus rex
by Mary H. Schweitzer, Jennifer L. Wittmeyer, John R. Horner, and Jan K. Toporski
in Science 25 March 2005; 307: pp 1952-1955 [DOI: 10.1126/science.1108397]
I've looked at the paper. It is quite fascinating, but there is no molecular analysis reported. The preservation appears remarkable, but the extent of relacement is unclear. From the conclusion of the scientific paper:
The elucidation and modeling of processes resulting in soft-tissue preservation may form the basis for an avenue of research into the recovery and characterization of similar structures in other specimens, paving the way for micro- and molecular taphonomic investigations. Whether preservation is strictly morphological and the result of some kind of unknown geochemical replacement process or whether it extends to the subcellular and molecular levels is uncertain. However, we have identified protein fragments in extracted bone samples, some of which retain slight antigenicity (3). These data indicate that exceptional morphological preservation in some dinosaurian specimens may extend to the cellular level or beyond.
ELIZA immunoassays were applied, and submitted as evidence of some molecular level preservation. There were also some elemental analysis, which looks to me to indicate atoms remaining from organic material (high carbon signal).
There was also a commentary article, but my connection broke before I could read it.
Cheers -- Sylas
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