A large pachycephalosaurian dinosaur of the genus Pachycephalosaurus, having a thick domed skull with bony knobs and a long tail. Also called pachycephalosaur.
[New Latin Pachycephalosaurus, genus name : Greek pakhus, thick + Greek kephalē, head; see ghebh-el- in the Appendix of Indo-European roots + Greek sauros, lizard.]
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