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Armored dinosaurs known as ankles may have used sledgehammer-like tail clubs against each other in conflict, in addition to warding off predators like the Tyrannosaurus rex.
A well-preserved fossil of an ankylosaurs, a plant-eating dinosaur that lived 76 million years ago, is changing the way scientists understand armored dinosaurs and how they used them. baton.
A study of fossils shows that the spines on the dinosaur’s flank were broken and healed while the animal was still alive. The researchers believe the injury occurred when another pterosaur stabbed its tail club into the dinosaur.
The study was published Tuesday in the journal Biology letter.
Ankylosaur has bony plates of various sizes and shapes on its body; Along the sides of its body, these plates act like large spikes. Scientists also believe that ankylosaurs may have used their weapon-like tails to assert social dominance, establish their territory, or even while fighting for mates.
Ankylosaurs used their tails to fight each other similar to how animals like deer and antelope use their antlers and horns to fight each other today.
The fossil is of a member of the specific ankylosaur species also known by its taxonomic name, cruiser Zuul. If the name sounds familiar, that’s because researchers borrowed Zuul’s name from a monster in the 1984 movie “Ghostbusters.”
The dinosaur’s full name means “Zuul, the shin destroyer”, as the ankylosauropod’s tail club is believed to be the enemy of tyrannosaurs and other predators. straight with the hind legs.
These tails are up to 10 feet (3 meters) long, with rows of spikes along the sides. The tail end is reinforced with bony structures, creating a club that can be swung with the force of a sledgehammer.
The skull and tail were the first fossil fragments to emerge in 2017 from a excavation site in the Judith River Formation in northern Montana, and paleontologists have been working for years to free the remains of the remains. fossils from 35,000 pounds of sandstone. The fossil is so well preserved that the skin and bony armor on the dinosaur’s back and sides remain, giving it a very lifelike appearance.
This particular species of ankles appears to be quite aggressive towards the end of life, with spikes near the hips and flanks missing the spikes. After enduring these injuries, the bone heals into a much more blunt shape.
Because of the location on the body, researchers do not believe the wound was caused by a predator attack. Instead, the pattern looks like the result of receiving a powerful blow from the tail club of another pterosaur.
Lead author of the study, Dr Victoria Arbour, curator of paleontology at the Royal British Columbia Museum in Victoria, Canada, said: “I was interested in how the ankles were used. their tails for many years and this is a really exciting new piece. , in a statement.
“We know that pterosaurs can use their tail clubs to deliver very powerful blows to their opponents, but most people think they are using their tail clubs against predators. Instead, ankylosaurs like Zuul might have fought each other.”
Arbor theorizes that the ankylosaurs may have been involved in their behavior years ago, but fossil evidence of wounds is needed – and ankle fossils are rare.
The particular Zuul crurivastator fossil helped fill that knowledge gap.
“The fact that the skin and armor are left in place is like a snapshot of what Zuul looked like when it was alive. And the injuries Zuul suffered during its lifetime tell us about how it might have behaved and interacted with other animals in its ancient environment,” said study co-author, Dr. David Evans, Temerty President and curator of vertebrate paleontology at the Royal Ontario Museum in Toronto. in a statement.
The Zuul fossil is now kept in the vertebrate fossil collection of the Royal Ontario Museum.