The skin of the fossilized dinosaur shows bite marks

(CNN) – The skin of a 67 million-year-old dinosaur revealed bite marks and wounds from an ancient crocodile, and the way its flesh ripped through could explain why it was mummified.

Skin degrades much more easily than bones, so finding fossilized dinosaur skin is very rare.

New research on the 7-meter-tall Edmontosaurus, a species of herbivorous hadrosaur, found near the town of Marmarth, North Dakota, in 1999, sheds light on the factors that have allowed the skin to survive through eons.

“The bite marks were really unexpected,” Stephanie said. “It was thought that the soft tissues wouldn’t be preserved if they were damaged before they were buried, so it was the damage to the carnivores that got us thinking about how these fossils formed.” Department of Earth and Planetary Sciences at the University of Tennessee and co-author of the new study.

Paleontologists used to think that a dinosaur, or any prehistoric creature, would have to be buried very quickly in order to preserve the soft tissues, but that wasn’t the case with this poor hadrosaurus.

Researchers believe that the bite marks on the hadrosaur’s arm came from an ancient crocodile relative, but they are not sure what type of animal scratched or bit its tail, although it was likely larger. It is unclear whether the injuries to his arm and tail killed him or if they were inflicted by the scavengers after his death.

However, Drumheller explained to Horton that it was the misfortune of the dinosaurs that allowed their skin to survive.

“To put it in the least annoying way possible, piercing the skin allowed the gases and fluids associated with decomposition to escape. This allowed hollow skin to dry out. Of course, mummified skin like this can last for weeks to months.” Wet environments and the longer they last, the more likely they are to be buried and petrified.”

The bluish color of the fossilized skin is not thought to reflect the color of the dinosaur when it was alive. However, the high iron content in the rocks during the fossilization process may have affected them.

Although their color is often depicted as greenish-gray, the color of most dinosaurs is largely unknown. Studies on petrified feathers Of the dinosaurs, some were surprisingly colorful.

An artistic impression of how the dinosaur’s death could have been. Credit: North Dakota Geological Survey

However, hadrosaur skin provided a lot of information about the size and patterns of scales throughout the dinosaur’s body, as well as the amount of muscle mass as a function of skin expansion in that area.

“Skin degrades much more easily than bone, so different, less observable processes are needed to preserve the skin long enough to be buried and fossilized,” said co-author on the research Clint Boyd, chief paleontologist with the Geological Survey, of North Dakota. .

Boyd believes there are fewer than 20 real dinosaur mummies, with complete or nearly complete sets of soft tissue remains.

“To put it in context, I’ve found thousands of fossils in my career, but only one of them has preserved dermal impressions (a fingerprint of the leather, not the preserved leather itself) and I’ve never found one myself that has preserved leather,” Boyd said via email.

The research was published Wednesday in the academic journal PLUS ONE.