Pachycephalosaurus, meaning 'Thick headed lizard'.
About 4.6 metres (15 feet)
2 metres (6ft)
About 450kg (1000lb)
Fossils have been found in the western part of Modern North America
Plants, fruit and insects.
Late Cretaceous between about 85 and 65 million years ago.
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Pachycephalosaurus was a bipedal ornithischian (bird hipped) herbivore that lived during the late Cretaceous period. It had a distinctive domed shaped head about 25cm thick that was surrounded by bony bumps. The large head contained a small brain that gave Pachycephalosaurus a relatively low intelligence rating compared to some of the lizard hipped dinosaurs of the time. Pachycephalosaurus is thought to have lived in small groups or herds that browsed on vegetation and fruit.
Predators would have included carnivores like Albertosaurus and T-Rex that would have found Pachycephalosaurus a relatively easy meal, despite its very thick skull.
Pachycephalosaurus fossils were first found in Montana, USA, by William Winkley in 1938. Barnum Brown and Erich Schlaikjer jointly named Pachycephalosaurus in 1943. Fossils have been found in North America, Mongolia, Madagascar and the Isle of Wight, suggesting that Pachycephalosaurus was found far and wide during the Cretaceous period.