Paleontologists have discovered a new species of dinosaur with a softball-sized lump of solid bone on top of its skull. The species, which the researchers named Texacephale langstoni, was a plant-eating dinosaur about as big as a medium-sized dog that lived 70-80 million years ago. The team discovered skull fragments in Big Bend National Park and found that they represent a new genus of pachycephalosaur that is different from its northern neighbors.