D’Anastasio is an associate professor at the University of Chieti-Pescara in Italy and the lead author of the new study, published Thursday in the journal Scientific Reports. The study of Big John’s prominent injury — a large hole pierced right through thick bone — was carried out as the Triceratops horridus skeleton was being assembled from its fossilized parts by Zoic LLC of Trieste, Italy. Another author of the paper, Flavio Bacchia, is a director of the company.
Big John has the world record for the largest triceratops skull yet found — over 5 feet long — and was probably among the largest of its kind. Although triceratops were plant-eaters, they were also huge. It’s estimated an adult was around 30 feet long, and weighed more than 12 tons.
Much of that mass was in its gigantic head, which was studded with three large horns — two above the eyes and one on its nose — and protected by the bony frill around its neck.
Zoic specializes in fossil reconstructions, and the company purchased the Big John skeleton in 2020 from a commercial paleontologist who found it in South Dakota.
After publicity displays in Trieste and Paris, the restored skeleton was sold in October 2021 for more than $7 million — a record for a triceratops fossil — to a private owner who hasn’t been publicly identified.
Some feared scientific access to the skeleton would be restricted as a result. But D’Anastasio said the new owner has stated the triceratops skeleton will be made available for research, and samples of its fossilized tissues are now in the university’s museum.
The size and shape of the hole in Big John’s neck frill correspond perfectly with the horn of a triceratops of similar size. A “combat simulation” of triceratops fighting, performed using plaster casts of the horns, helped the scientists better understand the event, he said.
Examinations show the gash had started to heal when Big John died, perhaps six months later — and while there is no surviving evidence of any scars, the wound was probably covered with new skin, he said.
D’Anastasio won’t speculate on just why Big John was fighting another triceratops but he acknowledges that it may have been over mates, as many birds — the descendants of dinosaurs — do today.
Some scientists suggest the distinctive horns and neck frills of triceratops may have been mainly to protect them from other triceratops, rather than other types of dinosaurs that might have regarded them as food.
That would mean that the horns and neck frills of triceratops were used “not only as a display, but also as a means of attack and defense” against other members of their species, D’Anastasio said.
Commercial paleontologist Walter Stein said the Big John skeleton was up to 45 percent complete and the skull was up to 75 percent complete when he found it on a ranch in South Dakota in 2014, while the rest of it had long rotted away. (The missing bones were replaced in the reconstruction with casts of bones from other triceratops skeletons.)