Pachycephalosaurus (pack-EE-seff-AL-low-SAW-rus Meaning Thick-Headed Lizard) was a type of dinosaur that lived during the Late Cretaceous Period. It was located in the USA and it was discovered by Gilmore in 1931. It stood on 5-8 meters (16-26 feet) tall. Pachycephalosaurus was one of the famous "bone head" dinosaurs.
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