image: Protein sequences were obtained from 21 extant and two extinct organisms from public databases and tandem mass spectrometry. Using several phylogenetic algorithms, the non-avian Tyrannosaurus rex dinosaur groups with birds rather than reptiles. These results support evolutionary relationships based on morphology. This image relates to an article that appeared in the April 25, 2008, issue of the journal Science, published by AAAS. The study, by Dr. C.L. Organ and colleagues at Harvard University in Cambridge, Mass., was titled "Molecular Phylogenetics of Mastodon and Tyrannosaurus Rex." view more
Credit: Image © Science