Fossilized bones can reveal a wealth of details about animals, including their size, appearance, what they ate and any injuries they may have suffered. In a paper published in the journal Royal Society Open Science, researchers in Spain describe a swollen patch on the shinbone of an Iguanodon, which they say may be evidence of an advanced skin ulcer that had reached the underlying bone. If so, this could be the first time this type of response to a bacterial infection has been reported in a dinosaur.