The curved talon of a newly discovered dinosaur relative of Velociraptor has revealed that the claw was used as a weapon, scientists have discovered.
Battle damage found on the fossilized remains of the recently discovered species of raptor shows the impressive claw was not used as a walking aid or for show, as palaeontologists previously thought.
The 75-million-year-old dinosaur, named Talos sampsoni, is a relative of the more famous Velociraptor, popularised in the Jurassic Park movies.
Researchers have estimated Talos, who was discovered in the 1.9m-acre Grand Staircase Escalante National Monument in southern Utah, would have been around 2m long and weighed roughly 38kg.
The characteristic toe claw on the fossil identifies the find as a member of a rare group of feathered, bird-like therapod dinosaurs. Most significantly for paleontologists, damage to the animal's left foot suggests the talon was used as a weapon.
Scientists analysed the left toe using a high-resolution computed tomography (CT) X-ray scanner. The findings, published in the online journal Public Library of Science ONE, indicate the toe was either bitten or fractured before becoming infected.
"When we realised we had evidence of an injury, the excitement was palpable," said lead researcher Dr Lindsay Zanno, from the University of Wisconsin-Parkside in the US. "An injured specimen has a story to tell.
"Finding a decent specimen of this type of dinosaur in North America is like a lighting strike... it's a random event of thrilling proportions," she added.
"People have speculated that the talon on the foot of raptor dinosaurs was used to capture prey, fight with other members of the same species, or defend the animal against attack. Our interpretation supports the idea that these animals regularly put this toe in harm's way."