More than 70 million years ago in what's now Montana, the plant-eating hadrosaur Hypacrosaurus stebingeri roamed. A new study of H. stebingeri nestlings has found fossils of dividing cells, nuclei, and chromosomes—as well as tantalizing hints of preserved DNA.
For billions of years, DNA has served as life’s information molecule, containing instructions for how and when to build the proteins of living organisms. But how long can that biological information survive? In a provocative new study, an international team of researchers reveals dinosaur fossils that are so well preserved, some contain the outlines of cells—and structures that might have formed from the dinosaurs’ original DNA.
The study, published last week in National Science Review, takes a close look at two juvenile skull bones from the hadrosaur Hypacrosaurus stebingeri, a plant-eating dinosaur that lived in what’s now Montana about 75 million years ago.
Inside the tiny fossils, researchers can see what appear to be cells, some frozen in the process of dividing. Others contain darkened balls that look just like nuclei, the cellular structures that store DNA. And one cell even seems to contain dark, tangled coils that resemble chromosomes, the condensed strands of proteins and DNA that form during cell division.
“It’s a sub-cellular level of preservation that’s never been reported before in a vertebrate,” says Alida Bailleul, a...