It is thought that most dinosaur bones that are at least 65 million years old have all turned to stone, and so there is no hope of DNA or proteins surviving. But a study in 2007 showed that scientists may have been too hasty when proteins were successfully extracted from a Tyrannosaurus rex bone. Using special extraction methods, the scientists found what seems to be collagen, which is one of the major proteins found in our own bones. Why is this exciting to paleontologists? By comparing the dinosaur collagen to contemporary chicken collagen, scientists might be able to answer a question that has plagued them for years: how closely are birds and dinosaurs related?