For more than a century, paleontologists have explored the Hell Creek Formation in the western part of North America in search of new dinosaurs. The rocks preserve some of the last non-avian dinosaurs before the fifth mass extinction on Earth, including icons like Tyrannosaurus and Triceratops. Now, experts have discovered a new species of dinosaur from the Cretaceous layers, a turkey-sized creature that was initially thought to be a juvenile example of a different dinosaur.

"When Royal Ontario Museum paleontologist Gregory Funston was contacted about some caenagnathid bones found in Hell Creek, it turned out that the legs belonged to the famous hell chicken. “Initially, my colleagues and I thought the bones must belong to a juvenile Anzu because they were smaller than other specimens but larger than other species mentioned in 2001,” said Funston. However, when Funston and his co-authors examined the microscopic details within the bones, they found evidence that the legs represented a new species."