TIM EDWARDS - A beautifully preserved sample of fossilised Edmontosaurus skin shows the first definitive evidence of scarring in dinosaurs, according to scientists. The fossil suggests the duck-billed dinosaur had a narrow escape from a carnivorous dinosaur, which the researchers believe might have been a Tyrannosaurus rex.
The 3.5cm oblong scar appears on a fossil from the South Dakota Badlands (pictured above). Wrinkles radiate outwards from the scar in an apparent example of the wound contraction seen in modern injuries.
“Healing has never previously been reported in the fossil record,” says Bruce Rothschild, Professor of Medicine at Northeast Ohio Medical University and a research associate at the Biodiversity Institute of the University of Kansas. The study appears in Cretaceous Research (hat tip to Ker Than of NatGeo.com).
The skin sample was buried with a skull which shows signs of a severe injury which later healed. Although Rothschild and his co-author Robert DePalma, Curator of Vertebrate Palaeontology at the Palm Beach Museum of Natural History, could not be sure that the injuries were the result of the same incident, it is possible that they were.
“It was probably a claw or tooth injury,” says Rothschild of the scar, “although something else could have pierced the dinosaur.”
The bone trauma, meanwhile, was almost certainly inflicted by a large carnivore – “presumably a T. rex”. Quite how the Edmontosaurus escaped is open to debate, but they had hefty tails which could be swung at any tormentor, and could probably deliver a powerful kick with their hind legs, says Rothschild.
There is no way of knowing what ultimately killed the scarred hadrosaur or for how long it survived after its brush with death. Modern reptiles heal and produce scars in about 10 days, but bone takes longer to heal, says Rothschild, who was inspired to pursue this study by his experience of a captive Komodo dragon which needed surgery for a bone injury.
As far as he is aware, it is the only fossil scar that is known about, but Rothschild believes there must be more out there. This particular fossil skin sample was spotted purely by chance thanks to the diligence of a particularly attentive student.
He hopes his findings will encourage more research into dinosaur skin fossils to establish an evidence base for comparison of different samples. “Nobody has ever taken a cross section of skin,” he says, indicating that this would be an interesting direction for future research.
- Tim Edwards is the digital editor of Walking With Dinosaurs
- Photograph of fossilised Edmontosaurus scar used with permission