Prehistoric battle scars are evidence of triceratops jousting tournaments

Little Foot may have been the star of Don Bluth’s The Land Before Time, but he never would have found the Great Valley without a little muscle. Cera, who’s name was taken from the species name Triceratops, secretly had a heart of gold but wasn’t afraid of headbutting her way out of a problem. Three horns might not play with longnecks, but they did play with each other. And by play, we mean punch each other in the face with their horns.

At the end of the movie, our intrepid band of dinosaur — and one pterosaur — explorers lead their friends and family to a land of promise where they make ready for a life of peace together. In reality, Cera was potentially in for a life of head trauma at the hands, or horns, of her own species, according to a recent paper published in the journal Scientific Reports.

Ruggero D’Anastasio from the Department of Medicine and Aging Science at the University of Chieti-Pescara was a part of the team that analyzed a Triceratops horridus (Dr. Alan Grant's favorite dino from childhood) fossil found at the Hell Creek Formation in Montana. The specimen, affectionately called Big John, is a stunning example of the lumbering, extinct animals, but it was one relatively small feature of his remains which caught researchers’ attention.

“During the restoration, Flavio Bacchia, a co-author of the paper, noticed an opening in the frill of the animal. I went to see the fossil and realized it was probably a consequence of traumatic injury,” D’Anastasio told SYFY WIRE.

Photo: R. D’Anastio et al, Scientific Reports

Openings or holes in the frills of Triceratops, known to paleontologists as fenestrae, aren’t all that uncommon and there are variable explanations for them, depending on their characteristics. Symmetrical openings could be natural formations in the bone and even asymmetrical ones could indicate changes in the bone’s structure as the animal ages. Big John’s frill opening, however, carried signs of a more violent origin.

“In this case, the position was unusual and only on the right side. Around and inside the fenestra there is evidence of bone regrowth, so we are sure it was from a traumatic event,” D’Anastasio said.

The size and shape of the opening is consistent with a stab wound from the horn of another Triceratops. What’s more, the injury’s keyhole shape suggests the attacker’s horn pulled downward after penetrating the frill, resulting in a wound consistent with a stab and rip. To confirm their hypothesis, the team made a cast of a large horn from another Triceratops and used it to reconstruct how the injury might have occurred.

“The size and shape of the fenestra fits with the big horn of a Triceratops. The position of the hole can be explained by an attack from behind, that is the most probable event,” D’Anastasio said.

Photo: R. D’Anastio et al, Scientific Reports

Paleontologists had long suspected Triceratops might have used their horns to engage in head-to-head battle, and that likely was the case, but it turns out they also weren’t above stabbing each other in the back.

The bone regrowth apparent in Big John suggests he survived the attack and lived to fight another day. How long he survived is an open question and depends largely on the rate at which Triceratops could regrow bone. In any case, the evidence suggests he survived for at least six months. Perhaps more surprising are the unexpected physiological processes Big John’s body used to heal the injury.

“The characteristics are very similar to the ones we see in mammals during bone healing. We would like to study other traumas in order to be sure that the pathological mechanisms we observed in Big John are present in other Triceratops,” D’Anastasio said.

All things considered, it actually makes sense that Cera was so distrustful and aggressive. It’s a hard life when everyone you know has spears on their faces and they’re coming at you from behind. We’d probably be defensive too.