Bone headed-Acrotholus audeti

You've heard of Pachycephalosaurus, and Stygimoloch right? Well say hello to the latest member of the 'bone headed' family: Acrotholus. Discovered in the Milk River Formation of Alberta, Canada, by researchers from the University of Toronto Acrotholus may be the oldest member of the group yet to be discovered. It pre-dates Pachycephalosaurus by 20 million years, The bones date from rocks that are 85 million years old. Being the oldest Pachycephalosaur yet to be discovered it offers researchers insights into the evolution of the 'bone heads' Around the size of a dog and weighing in at 40Kg Acrotholus is a rather small Pachycephalosaur. And it's size also sets it apart from the rest. "We can predict that many new small dinosaur species like Acrotholus are waiting to be discovered by researchers willing to sort through the many small bones that they pick up in the field," said co-researcher Dr Michael Ryan, curator of vertebrate palaeontology at the Cleveland Museum of Natural History. It has long been suggested that there is not a truthful reflection of small Dinosaur fauna's in existence as their tiny bones may have been to small to properly fossilize. However Acrotholus shows that when it comes to Dinosaurs. The small are just as important as the big.