Pachycephalosaurs were one of the last dinosaur groups to appear. Most lived 80-66 million years ago.
The name Pachycephalosaurs means ‘thick-headed reptile’. due to the domed and hugely thickened bone on the top of it’s skull.

About 4.5 meters long from nose to tail, Pachycephalosaurs lived in the American Midwest.

It was an herbivorous or omnivorous creature which is primarily known from a single skull and a few extremely thick skull roofs, though more complete fossils have been found in recent years. Pachycephalosaurus was one of the last non-avian dinosaurs before the Cretaceous-Paleogene extinction event.