Pachycephalosaurus Skull

Back to list

Pachycephalosaurus Skull

‘P. wyomingensis’
Late Cretaceous Period, C. 68-66 Million Years Ago
Wyoming, USA
Fossilised Bone
H:33 cm x W:24 cm x D:41 cm



An extraordinarily rare skull of Pachysephalosaurus, the ‘thick-skulled lizard’, which lived around 65-68 million years ago in the late Cretaceous period of North America, alongside some of the most iconic dinosaurs such as Tyrannosaurus and Triceratops. It is known from only one species, P. wyomingensis, the adult forms of which are only known from skull remains. 
Probably herbivorous and bipedal, it is most famous for the large dome at the top of its head, which in some cases grew to be over 25cm thick and which it may have used as a weapon, to head-butt predators and rivals. Pachycephalosaurus is notable for having drastic ontogenetic stages (juvenile skeletons look significantly different from adult), so much so that two of its juvenile forms were originally assigned to different genera; Dracorex and Stygimoloch. 

Given that to this date only skulls have been found, the exact size and shape of its body can only be estimated, and reproductions are based upon more complete relatives, such as those of the Stegoceras.  


Discovered on private land belonging to Dave and Lynette Donahey, Carter County, Montana, USA at GPS Coordinates: N 45 28.843 / W 104 10.866.  
Excavated by Craig Pfister of Greater Plains Palaeontology.  
With IADAA certificate, this item has been checked against the Interpol database.