CollectA PachycephalosaurusCollectA Pachycephalosaurus CollectA model 88629 Product Dimensions: 10 x 4 x 5. 7 cm Age: 3 years and up The Pachycephalosaurus was a unique dinosaur that lived around 70 million years ago in what is now North America. Its name means "thick headed lizard," and for good reason it had an incredibly thick, dome shaped skull. This special skull could have been up to 10 inches thick! Scientists believe this dinosaur might have used its hard head in head