The afflicted dinosaur was discovered in what is now southern New Jersey. Researchers only recovered its two forearm bones — the radius and ulna, so they can’t tell exactly what species it was. However, they do know that it was probably a duck-billed dinosaur, known as a hadrosaur, and that it lived about 70 million years ago.
Both bones were covered with a strange bony growth the texture of cauliflower. Further investigation revealed that the elbow joint had completely eroded away and then fused.
“It probably had a partially bent arm with either little or no movement at the elbow. Kind of like Igor from ‘Frankenstein,'” said first author Jennifer Anne, who recently completed her PhD from the University of Manchester in Britain. “It also probably would have had a limp.”
The researchers said it is hard to tell how much agony the situation caused the dinosaur.
“Reptiles and birds both deal with horrific injuries, so although I’m sure it hurt, it probably trudged through,” Anne said.
She first heard about the unusual dinosaur bones a little over a decade ago.
“We have been scheming to scan it for almost 10 years,” she said. “We just needed the right equipment.”
Like many fossils discovered in this part of New Jersey, these two specimens are extremely fragile. That’s because the area was under the ocean 70 million years ago, and the dinosaurs that have been found there are what are called “bloat and float deposits. Fossils that were deposited this way are prone to a condition called pyrite disease that can cause them to turn to dust when they are touched.
Since the researchers couldn’t slice the fossil to peer inside it, Anne and her collaborators used the microCT scanning facilities at the Center for Nanoscale Systems at Harvard University. Medical CT scanners are powerful enough to see through bone, but the investigators needed one that could see through rock.
After comparing the dinosaur’s symptoms to those seen in other animals, the researchers ultimately concluded that their specimen suffered from septic arthritis, which is caused by an infection in a joint.
In modern-day reptiles, the condition is usually contained to the area where the infection began, but when mammals get it, it often spreads to multiple areas of the skeleton, Anne said.
“Unfortunately, we don’t have the rest of the hadrosaur to see how far it might have spread, though I’m betting it would have at least affected the humerus [upper arm bone] at the elbow joint as well,” she said.
Poor ancient dinosaur.