Armored Dinosaurs Didn’t Just Use Their Hammer Tails To Fight Tyrannosaurus

Some dinosaurs are automatically cool. Scary T. rex. Horned Triceratops. Spiny Ankylosaurs – stocky, armored dinosaurs with wicked club-like tails. Paleontologists have long thought these tails were used to ward off predators like T. rex, but new research suggests they may also have been used for internal fighting.

A team of researchers from the Royal Ontario Museum (ROM), the Royal BC Museum and the North Carolina Museum of Natural Sciences published a study this week in Biology Letters on a remarkable and rare crurivastator Zuul fossil. The ankylosaurus had damaged and scarred spikes near its hips. Scientists suspect the injuries came from another ankylosaur that delivered a mighty blow with its own “hammer-like tail.”

Zuul’s crurivastator may have become petulant with his own, much like modern-day deer, kangaroos, and zebras. “This suggests that ankylosaurs exhibited complex behavior, possibly struggling for social and territorial dominance or even engaging in a season of ‘rut’ for mates,” ROM said in a statement Tuesday.

Herbivorous ankylosaurs lived 76 million years ago. It took years of excavation work in Montana to extract the fossil of the crurivastator Zuul at the heart of the study. Fossilized skin and armor show wounds where spikes were broken off and then healed into a blunt shape, a pattern more consistent with fighting other ankylosaurs than attacking a predator like a tyrannosaur.

As an aside, the Zuul Crurivastat Name is worth exploring further. Zuul is for the Horned Guardian from Ghostbusters, while the rest of the moniker translates to “shredder of shinbones,” a reference to how dinosaurs likely used their tails to pull out the legs of tyrannosaurs. Maybe he needs a new nickname: Zuul, Flank Destroyer.