The tiny fossil is unassuming, as dinosaur remains go. … 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. [P]aleontologists 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.
The question is whether these proteins and other traces are really what they seem. [A] separate team, led by Princeton University geoscientist Renxing Liang, recently reported on unexpected microbes found inside one from Centrosaurus, a horned dinosaur of similar age to Hypacrosaurus. The researchers said that they unearthed DNA inside the bone, but it was from lineages of bacteria and other microorganisms… . The bone had its own unique microbiome, which could cause confusion as to whether proteins and possible genetic material belonged to the dinosaur itself or to bacteria.