A dinosaur has been diagnosed with severe arthritis 70 million years after its death.
Scientists believe the hadrosaur, a plant-eating duck-billed dinosaur, must have endured considerable suffering before reaching the end of its life.
X-ray analysis of its fossilised elbow joint revealed evidence of septic arthritis, an especially nasty form of the disease caused by infection and known to afflict modern birds, crocodiles and humans.
A micro-tomography scan — a high resolution version of the kind of CT scans used in hospitals — showed that the joint was fused and covered in bony growths.
It is the first time septic arthritis has been seen in a dinosaur, although another arthritic condition called osteomyelitis was quite common among the creatures.
In this case, osteomyelitis was ruled out because of the “highly reactive” bone growth and the location of the affected area around the elbow joint.
Life of suffering
“To the best of our knowledge, this is the first recorded account of septic arthritis in dinosaurs,” wrote the team led by Jennifer Anne, from the University of Manchester, in the UK.
“The severity of the pathology suggests the animal suffered with this condition for some time before death.”
Non-destructive analysis of the fossil was made possible by having access to the microCT scanning facility at Harvard University, in the US.
The ulna and radius bones suffered from a geological condition called pyrite disease, which can cause fossils to crumble to dust.
The researchers narrowed their diagnosis down after excluding cancer, gout – which is common in reptiles – tuberculosis, and the poultry disease osteopetrosis.
Journal reference: Royal Society Open Science, doi: 10.1098/rsos.160222
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