Art #8: Three Pachycephalosaurs

"Three Pachycephalosaurs"
Coloured pencil illustration, July 2008
Adapted from Luis Rey's illustrations in Dinosaurs: The Most Complete, Up-To-Date Encyclopedia for Dinosaur Lovers of All Ages

Top: Stegoceras validum Lambe, 1902
Pachycephalosauridae; Marginocephalia; Ornithischia; Sauropsida; Chordata
From Late Cretaceous North America

Middle: Pachycephalosaurus wyomingensis Gilmore, 1931
Pachycephalosauridae; Marginocephalia; Ornithischia; Sauropsida; Chordata
From Late Cretaceous North America

Bottom: Dracorex hogwartsia Bakker et al., 2006
Pachycephalosauridae; Marginocephalia; Ornithischia; Sauropsida; Chordata
From Late Cretaceous North America

The pachycephalosaurs, or "bone-heads" are known to be the closest relatives to the ceratopsians, or "horned faces", like the well known Triceratops. They both share the formation of thickened bone around the edges of the head (hence "Marginocephalia"), which in the advanced ceratopsians is turned into a frill. The most well known pachycephalosaur is the quite hard to pronounce and spell Pachycephalosaurus, meaning "thick-headed lizard". It is probably obvious that these animals used their thickened skulls for protection or fighting, but the bone, although thick, might have been fragile and easily shattered, so probably not for head on fighting. 

While Stegoceras ("roof head") and Pachycephalosaurus have been known for around a century, Dracorex hogwartsia was discovered very recently and named as a new species and genus. My colour scheme for this animal was influenced by both parts of its name: Dracorex means "king dragon" in Latin, and hogwartsia honours the Hogwarts School of Witchcraft and Wizardry in J K Rowling's world-famous Harry Potter series of books. The colours of Gryffindor house in the books are red and gold, and both also look quite draconian, in the true sense of the word, meaning "dragon-like". Despite all this, Dracorex might prove to just be a juvenile Pachycephalosaurus, and it would be a shame to lose this most magnificent of recent dinosaur names, most of which seem to be named after a locality and/or a person.

I realised while drawing Stegoceras that my picture was going to look a bit like George Washington, so the colours were likewise influenced by the United States. The colour scheme for Pachycephalosaurus is based on a "rhubarb and custard" combination I quite like.