A new study from North Carolina State University identifies vertebrate hemoglobin in bone extracts from two dinosaurs and shows that this molecule is original to those animals. The work also shows how heme, a small molecule that gives hemoglobin the ability to transport oxygen in blood, degrades over time. The study both adds to the body of evidence that biological remains can and do persist across deep time in some fossils and provides further insight into the process of fossilization.