Researchers have discovered clear chemical traces of decaying collagen in a duck-billed dinosaur fossil, upending previously held notions that any organic material found within such ancient fossils must be from some source of contamination.

“This research shows beyond doubt that organic biomolecules, such as proteins like collagen, appear to be present in some fossils,” says University of Liverpool materials scientist Steve Taylor.

“Our results have far-reaching implications. Firstly, it refutes the hypothesis that any organics found in fossils must result from contamination.”