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Iron explains preservation of dinosaur soft tissue



From: Ben Creisler
bcreisler@gmail.com


A new paper:

Mary H. Schweitzer, Wenxia Zheng, Timothy P. Cleland, Mark B. Goodwin,
Elizabeth Boatman, Elizabeth Theil, Matthew A. Marcus, and Sirine C.
Fakra (2013)
A role for iron and oxygen chemistry in preserving soft tissues, cells
and molecules from deep time.
Proceedings of the Royal Society: B 281: 1775 20132741
doi: 10.1098/rspb.2013.2741
http://rspb.royalsocietypublishing.org/content/281/1775/20132741.abstract


The persistence of original soft tissues in Mesozoic fossil bone is
not explained by current chemical degradation models. We identified
iron particles (goethite-αFeO(OH)) associated with soft tissues
recovered from two Mesozoic dinosaurs, using transmission electron
microscopy, electron energy loss spectroscopy, micro-X-ray diffraction
and Fe micro-X-ray absorption near-edge structure. Iron chelators
increased fossil tissue immunoreactivity to multiple antibodies
dramatically, suggesting a role for iron in both preserving and
masking proteins in fossil tissues. Haemoglobin (HB) increased tissue
stability more than 200-fold, from approximately 3 days to more than
two years at room temperature (25°C) in an ostrich blood vessel model
developed to test post-mortem ‘tissue fixation’ by cross-linking or
peroxidation. HB-induced solution hypoxia coupled with iron chelation
enhances preservation as follows: HB + O2 > HB − O2 > −O2 ≫ +O2. The
well-known O2/haeme interactions in the chemistry of life, such as
respiration and bioenergetics, are complemented by O2/haeme
interactions in the preservation of fossil soft tissues.

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Press release and news stories:

http://news.ncsu.edu/releases/schweitzer-iron/

http://www.livescience.com/41537-t-rex-soft-tissue.html

http://www.sciencedaily.com/releases/2013/11/131126191433.htm