Pachycephalosaurus by SchleichPachycephalosaurus by Schleich. Hand painted dinosaur figurine by Scheich. The Pachycephalosaurus is the largest beaked, herbivorous dinosaur ever discovered. It grew to around 4 5 m in length, 450 kg, moved on two legs and lived in the Late Cretaceous period in North America. I t's strong domed skull was 20 25 cm thick. Scientists believe that it used the skull to ram or impress rivals. Pachycephalosaurus means thick headed lizard.Includes booklet.