A newly discovered dome-headed, dog-size dinosaur suggests that small dinos were more diverse than paleontologists have realized.
The dinosaur, discovered in Alberta, Canada, is named Acrotholus audeti; Acrotholus means "high dome," as the new dinosaur was a pachycephalosaur, a group known for their thick, bony skulls. The new specimen is the oldest pachycephalosaur ever found in North America, and rivals the oldest specimen in the world, scientists report today (May 7) in the journal Nature Communications.
"Acrotholus provides a wealth of new information on the evolution of bone-headed dinosaurs. Although it is one of the earliest known members of this group, its thickened skull dome is surprisingly well-developed for its geological age," study researcher David Evans, the curator of vertebrate paleontology at the Royal Ontario Museum, said in a statement. [Gallery: Gorgeous Dinosaur Fossils]
The dinosaur roamed in what is now Alberta about 85 million years ago. That's 5 million years before the next known pachycephalosaur specimen found in North America. Another pachycephalosaur from Mongolia is approximately the same age as the new species.