A spectacular dinosaur discovery in Spain is giving scientists a rare new look inside the world of stegosaurs. Paleontologists uncovered the best-preserved stegosaur skull ever found in Europe, belonging to the iconic plated dinosaur Dacentrurus armatus, which roamed Earth around 150 million years ago. Because stegosaur skulls are extremely fragile and almost never survive intact, the fossil is helping researchers uncover previously unknown details about how these armored giants evolved.