Introduction
The mass extinction of the dinosaurs, marked by the Cretaceous-Tertiary boundary, pales in magnitude compared to other lesser known mass extinction events, such as the Permian-Triassic boundary. As over 99% of all of the species that ever lived are now extinct, our understanding of biological processes has been limited by what we have learned from the fewer than 1% of species that have survived more than five major mass extinction events. Recently, collagen peptides were reportedly recovered from mineralized skeletal elements of Tyrannosaurus rex and Brachylophosaurus canadensis [1,2], indicating that proteins could be preserved over geological time spans.