In 2007, a group of investigators, led by John Asara of the Beth Israel Deaconess Medical Center and Mary Schweitzer of North Carolina State University, announced in Science that they had sequenced collagen from a 68 million-year-old Tyrannosaurus rex by mass spectrometry. The T. rex was the oldest fossil to date to have its protein sequenced. On the basis of data collected from seven peptides, the authors concluded that the T. rex's collagen resembled that of chicken.
But as the headlines about the T. rex–chicken link hit major newspapers, so did questions about the work. Getting sequence data from fossils aged 1 million years or older has been the Achilles’ heel of the molecular paleontology field. So when Asara, Schweitzer, and colleagues reported they had identified, sequenced, and taxonomically classified a protein from a 68 million-year-old dinosaur, it obviously made other experts curious as to how they managed to do it. Scrutiny of the paper followed.
The controversy over this high-profile paper has been brewing for the past 18 months and likely won't die any time soon. The raw mass spectra that Asara and colleagues collected are now available on the publicly accessible PRIDE database so that others can assess whether or not the data and original conclusions are sound.