Reanalysis of Tyrannosaurus rex Mass Spectra. 2009. M. Bern et al. Journal of Proteome Research.
A new analysis of the remains of a T. rex that roamed Earth 68 million years ago has confirmed traces of protein from blood and bone, tendons, or cartilage. The findings are the latest addition to an ongoing controversy over which biochemical remnants can be detected in the dinosaur.
The authors point out that the first analysis in 2007 of a well-preserved, fossilized T. rex bone identified traces of seven distinct protein fragments, or peptides, from collagen. That material is one of the primary components of bone, tendons and other connective tissue. However, later studies disputed that finding, suggesting that it was a statistical fluke or the result of contamination from another laboratory sample.
The scientists describe reanalysis of the T. rex data and also report finding evidence of substances found in collagen. "In summary, we find nothing obviously wrong with the Tyrannosaurus rex [analysis from 2007]," the report states. "The identified peptides seem consistent with a sample containing old, quite possibly very ancient, bird-like bone, contaminated with only fairly explicable proteins. Hemoglobin and collagen are plausible proteins to find in fossil bone, because they are two of the most abundant proteins in bone and bone marrow." link