A team of scientists have uncovered three dog-sized dinosaur specimens. The fossilized bones, around 85 million years old, were found on a farm in Alberta, Canada. The species, Acrotholus audeti, weighed 85 pounds when it lived and is the oldest known pachycephalosaur from North America and maybe even the world. The Acrotholus audeti had a skull more than two inches thick. Scientists sometimes refer to pachycephalosaurs as thick-headed lizards or bone-headed dinosaurs because of their skulls.