“Big John” by name was Big John by nature, being one of the largest specimens discovered in the Hell Creek Formation and the biggest triceratops ever found to date, with a bony collar that’s 2 x 2.62 meters (6.5 x 8.5 feet) across. His remains date back to the Cretaceous around 66 million years ago, but they have delivered fresh insights into triceratops' battling lifestyle in a new paper.

Injuries sustained to Big John’s collar may have been the result of a fight with another triceratops, says the new study published in Scientific Reports. The damage sustained in this prehistoric fight resulted in a keyhole-shaped puncture called a fenestra.

Around the hole were signs of plaque-like deposits of bone, which the researchers on the new paper believe could have developed following inflammation perhaps due to an infection. This kind of irregular healing of wounds is something that’s associated with trauma to bone.

They decided to take a closer look by analyzing samples from the fossilized remains, including bone segments taken from around the fenestra. The analyses revealed that the bone was highly porous and would’ve housed lots of blood vessels, all indicators that the bone was newly formed compared to that which makes up the rest of Big John’s collar.

There were also little pits called Howship lacunae on the bone samples, which are a sign that remodeling is taking place. Combined, this evidence of inflammation and remodeling points to the injury as being one born of combat that subsequently did some healing.

As for what punctured Big John’s big collar, the researchers believe it’s likely that the dinosaur may have sustained the injury during a fight with another triceratops whose horn pierced the dinosaur. The enormous bony collars of triceratops are believed to have served a protective function for these animals, so they would have been a common site for traumatic injury.

The triceratops Fight Club wasn’t fatal for Big John, however, and probably happened around six months before its death. This estimate is based on the fact that there’s evidence of inflammation and remodeling around the injury site, demonstrating that the dinosaur was alive for some time following the incident.

Interestingly, the healing process appears to share many features with that seen in extant mammals. We might not be enormous, armored, and intimidating beasts, but complex, messy ways of healing are one thing we may have had in common with the dinosaurs.

Something to remind yourself of the next time you roll your ankle stepping off a curb.