Geologist Dr Joe Peterson, of Northern Illinois University, said: “Jane has what we call a boxer’s nose. Her snout bends slightly to the left. It was probably broken and healed back crooked.”
Because the dinosaur had not reached maturity, the researchers said it was unlikely the combat was over sexual conflict or competition but might have been a learning behaviour for young dinosaurs prompted by a show of dominance or territorial dispute.
Dr Peterson says other adolescent animals, particularly juvenile crocodiles, exhibit such fighting behaviour.