The tiny fossil is unassuming, as dinosaur remains go. It is not as big as an Apatosaurus femur or as impressive as a Tyrannosaurus jaw. The object is a just a scant shard of cartilage from the skull of a baby hadrosaur called Hypacrosaurus that perished more than 70 million years ago. But it may contain something never before seen from the depths of the Mesozoic era: degraded remnants of dinosaur DNA.
Genetic material is not supposed to last over such time periods—not by a long shot. DNA begins to decay at death. Findings from a 2012 study on moa bones show an organism’s genetic material deteriorates at such a rate that it halves itself every 521 years. This speed would mean paleontologists can only hope to recover recognizable DNA sequences from creatures that lived and died within the past 6.8 million years—far short of even the last nonavian dinosaurs.
But then there is the Hypacrosaurus cartilage. In a study published earlier this year, Chinese Academy of Sciences paleontologist Alida Bailleul and her colleagues proposed that in that fossil, they had found not only evidence of original proteins and cartilage-creating cells but a chemical signature consistent with DNA.