Birds Evolved From Dinosaurs
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Posted by Rosemary Drisdelle May 7, 2007 |
Amazingly, scientists have been successful in recovering proteins from fossils of a Tyrannosaurus rex that died in Hell Creek, Montana, 68 million years ago. The protein is collagen, a connective tissue found in bone, and because the fossils were buried under rock, the protein has not been compromised by bacteria or water.
Comparison of the molecular structure of the T. rex protein with proteins from animals alive today found the best match was with chicken collagen. The hypothesis that birds evolved from chickens, formerly based on similar bone structure, now has strong scientific evidence to back it up.
Now that we know that proteins can sometimes be recovered from very ancient fossils, paleontologists will be looking for fossils in certain ideal places—places isolated from water and bacterial contamination. Fossils buried in sand or preserved in sandstone are good candidates. Perhaps it won’t be long before more such fossils provide overwhelming evidence that dinosaurs are still with us—at our bird feeders.
If you’re keen to read the April 2007 articles published in Science, here are the citations:
Analyses of Soft Tissue from Tyrannosaurus rex Suggest the Presence of Protein, by Mary Higby Schweitzer, Zhiyong Suo, Recep Avci, John M. Asara, Mark A. Allen, Fernando Teran Arce & John R. Horner. Science 316:277-280 (13 April 2007).
Protein Sequences from Mastodon and Tyrannosaurus rex Revealed by Mass Spectrometry, by John M. Asara, Mary H. Schweitzer, Lisa M. Freimark, Matthew Phillips & Lewis C. Cantley. Science 316:280-285 (13 April 2007).
Other blog posts and articles on bird paleontology:
World of the Dodo Birds Revealed
Sources:
Living the Scientific Life. Tyrannosaurus rex Protein Reveals Dinosaurs' Closest Relative: Birds
April 13, 2007
Schmid, Randolph. T. rex Proteins Most Resemble Birds. presstelegram.com April 12, 2007.