Dinosaur that broke its wrist may have fallen while mating

By Carissa Wong.

In what is now eastern Russia, a four-legged duck-billed dinosaur broke its wrist when it fell from an upright position while reaching for leaves.

The Royal Belgian Institute of Natural Sciences' Filippo Bertozzo says that it was standing on its heels for maybe eating, or just passing time, when it fell.

The discovery of a dinosaur lower foreleg bone in Blagoveshchensk in southeast Russia was made by using a form of X-ray technology.

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The bone is usually slender, smooth and regular, but in this case it had a huge swelling at its wrist end.

The hadrosaur bone was analysed by the team and it was found to be a herbivorous hadrosaur which lived in herds of hundreds of individuals. The animal was around 5 metres long and 2 metres high.

The team analysed a digital reconstruction of the bone and found that the dinosaur probably fell from an upright position which caused a diagonal fracture at the end of the ulna. Overgrowth of the bone occurred during the healing process.

The structure that protects the bone during the healing process is completely surrounded by the fractured bone.

The extent of healing in the dinosaur's bone suggests it would have been able to walk for at least four months before it died.

When you die, your body cannot heal, so we can be certain that the injury didn't kill the dinosaur.

It's impressive to think about how strong these animals were. It would have been difficult to walk and run after that.

The hadrosaur may have been protected by hiding in the middle of herds, but more data is needed to establish whether the herd helped to care for it.

The journal reference is Historical Biology.

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