Tuesday, April 24, 2007

A T-Rex would have tasted like Chicken



Protein extracted from a 68-million-year-old Tyrannosaurus rex bone has provided further evidence of a direct evolutionary line between dinosaurs and birds.

The soft tissue was removed from a fossilised thigh bone belonging to one of the giant predator dinosaurs unearthed in the US state of Montana in 2003. It lay under more than 1,000 cubic metres of rock.

Scientific analysis showed the tissue, which belongs to the elastic fibres known as collagens, was similar in structure to chicken protein, say scientists writing in the journal called Science.

The tissue is thought to have survived because it did not come into contact with atmospheric or groundwater contamination.

The same researchers hit the headlines two years ago with the discovery that the fossil seemed to contain soft tissues, including blood vessels. Both operations on the T. Rex bone were performed at North Carolina State University in Raleigh.

Collagen is a fibrous, elastic protein that also helps to keep skin looking young. It also makes up most of the organic material in bone, which consists of both minerals and protein.

The process of fossilisation takes place over millions of years when organic remains are replaced by minerals from water and rock.

"For centuries it was believed that the process of fossilisation destroyed any original material, consequently no-one looked carefully at really old bones", said Dr Mary Schweitzer, who led the North Carolina team.

Final confirmation came from the laboratory of Dr John Asra, director of a mass spectrometry facility at Beth Israel Deaconess Medical Centre in Boston.

Mass spectrometry is a sensitive technique that identifies chemicals by their atomic mass. It was able to show the T. rex material contained sequences of amino acids. These are the protein building blocks typical of collagen.

The sequence pattern looked like that of chicken collagen, and there were also similarities with frog and newt protein. "The similarity to chicken is definitely what we would expect given the relationship between modern birds and dinosaurs," said Schweitzer.

"This data will help us learn more about dinosaurs' evolutionary relationships, about how preservation happens, and about how molecules degrade over time, which could also have some important medical implications for treating disease", said Schweitzer. dpa mb pb ds




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