Sign up for CNN’s Wonder Theory science newsletter. Explore the universe with news of exciting discoveries, scientific advances and more.
CNN
—
The skin of a 67-million-year-old dinosaur has revealed bites and cuts from an ancient crocodile, and how its flesh decomposed may explain why it was mummified.
Skin decays more easily than bone, so finding fossilized dinosaur skin is extremely rare.
A new study of the 7-meter (23-foot) long Edmontosaurus, a herbivorous hadrosaur found in 1999 near Marmart, North Dakota, sheds light on what factors allowed the skin to last eons.
“The bite marks were really unexpected. “It was thought that soft tissue would not be able to protect it if it was damaged before burial, so the carnivore damage made us wonder how these fossils were formed,” he said. The University of Tennessee’s Department of Earth and Planetary Sciences co-authored the new study.
Paleontologists used to think that a dinosaur, or any prehistoric creature, had to be buried very quickly to preserve the soft tissue – but that wasn’t the case for this poor hadrosaur.
Researchers think the bite marks on the hadrosaur’s arm came from an ancient relative of the crocodile, but they aren’t sure which animal bit its tail or whether it was bigger. It is not clear if the wounds to his arm and tail killed him or if he was shot by scavengers after his death.
However, Drumheller-Horton explained that the dinosaur’s misfortune allowed it to preserve its skin.
“Trying to put it in the least disgusting way possible—puncturing the skin allowed the gases and fluids associated with decomposition to escape later. This left the hollow skin to dry out. Natural mummified skin like this can last for weeks to months even in fairly moist environments, and the longer it lasts, the more likely it is to undergo burial and fossilization,” he said.
The blue color of the fossilized skin is not thought to reflect what the dinosaur would have been like when it was alive. However, it may have been affected by the high iron content in the rocks during the fossilization process.
Although often described as greenish gray, it is unknown what color most dinosaurs were. Fossil studies dinosaur feathers revealed that some were surprisingly colorful.
And the skin of a hadrosaur provided a lot of information about the size and patterns of scales on the dinosaur’s body, as well as the amount of muscle mass—based on how wide the skin was in that area.
“Skin breaks down more easily than bones, so different and less-observable processes are required to preserve skin long enough to bury and fossilize,” said study co-author Clint Boyd, senior paleontologist at the North Dakota Geological Survey.
He said there are fewer than 20 true dinosaur “mummies,” complete and nearly complete fossil sets with soft tissue.
“I have found thousands of fossils in my career, but only one of those preserved skin impressions (an impression of skin, not the actual preserved skin itself), and I myself have never found one with skin. preserved,” Boyd said via email.
Published in a research journal Wednesday in the journal PLOS One.
