How did armored dinosaurs use their tail clubs? New research reveals more

Meet ankylosaurs, a.k.a Zuul

Zuul is a herbivorous ankylosaurine dinosaur genus from Montana's Campanian Judith River Formation. Zuul crurivastator is the type species. This species is known for its whole skull and tail club. As mentioned in the release, the 76-million-year-old, plant-eating dinosaur's skull and tail had been freed from the surrounding rock, but the body was still encased in 35,000 pounds of sandstone.

With the huge effort of the scientists over many years, Zuul's body was unearthed, that most of the skin and bony armor across the entire back and flanks. After taking shape, it finally revealed by scientists what the dinosaur looked like a million years ago.

A number of spikes around the hips on both sides of the body have lost their tips, and the bone and horny sheath have healed into a blunter shape, which the scientists found to be intriguing. Due to the location of the injuries on the body, it is more likely that they were caused by some sort of ritualized combat or jousting with their tail clubs rather than by an approaching predator like a tyrannosaur.

“I’ve been interested in how ankylosaurs used their tail clubs for years, and this is a really exciting new piece of the puzzle,” says lead author Dr. Victoria Arbour, Curator of Palaeontology at the Royal BC Museum and former NSERC postdoctoral fellow at the Royal Ontario Museum.

“We know that ankylosaurs could use their tail clubs to deliver very strong blows to an opponent, but most people thought they were using their tail clubs to fight predators. Instead, ankylosaurs like Zuul may have been fighting each other.”

Apart from all of this, the study does not invalidate the hypothesis that tail clubs could have been employed in self-defense against predators, but it does reveal that tail clubs could have also been used for intra-species battles.

“The fact that the skin and armor are preserved in place is like a snapshot of how Zuul looked when it was alive. And the injuries Zuul sustained during its lifetime tell us about how it may have behaved and interacted with other animals in its ancient environment,” said Dr. David Evans, Temerty Chair and Curator of Vertebrate Palaeontology at the Royal Ontario Museum.