Pachycephalosaurus was a unique herbivorous dinosaur that lived during the Late Cretaceous period, around 70 million years ago. Native to what is now North America, it was known for its thick, domed skull, which could reach up to 10 inches in thickness. This distinctive feature has led scientists to believe it may have been used for head-butting in dominance displays or territorial disputes. Growing up to 15 feet long and weighing nearly 1,000 pounds, Pachycephalosaurus had a bipedal stance, short arms, and a strong, rigid tail for balance. Despite its intimidating skull, it primarily fed on soft vegetation, fruits, and possibly seeds. Its mysterious behavior and iconic head structure make it one of the most recognizable dinosaurs of its time.