Dracorex: Prehistoric Animal of the Week

My birthday is later this month so until then we will be reviewing my favorite creatures.  Yes, as the author AND illustrator of these things I totally have that power (MWAHAHAHA).  So today we are looking at a member of one of my favorite dinosaur families, the pachycephalosaurids, with quite possibly the coolest name in dinosaur history, Dracorex hogwartsia!

Dracorex's full name translates to "Dragon King from Hogwarts".  Yes, Hogwarts, as in the school of witchcraft and wizardry from J.K. Rowling's Harry Potter series.  This is because its skull, which is adorned with many horns and spikes, resembles that of a mythical dragon's which could have existed in the Harry Potter universe.  Dracorex lived in what is now South Dakota in the United States about 67 to 66 million years ago during the late Cretaceous period.  It was about ten feet long and would have mostly eaten plants when alive.

Dracorex hogwartsia life reconstruction by Christopher DiPiazza

There is actually quite a bit of paleontologist drama surrounding this little dinosaur.  Not long after it was discovered and described, a few paleontologists decided that Dracorex was in fact not deserving of being a species of dinosaur.  They didn't deny it existed, of course.  They believe that Dracorex was actually a juvenile of another already discovered dinosaur, Pachycephalosaurus, which would have co-existed with it.  Comparing the two animals in question, you will notice that Pachycephalosaurus has an extremely thick dome-shaped helmet for a skull surrounded by small horns while Dracorex has a flat head covered in proportionally longer horns.  The idea is that as the Dracorex(or juvenile Pachycephalosaurus?) got older, its skull drastically changed shape to eventually become a thick dome for fighting rival adults.  This theory doesn't sound impossible (nature is freaking weird) but there is far from enough real evidence to prove it officially.  Also, dramatic change in skull shape like horns being absorbed into the skull to form a dome is unheard of in large vertebrates.  Most of the time when dramatic changes take place during an animal's development it happens with soft tissue bits, not bone.

Dracorex skeletal mount.

Some folks who argue that Dracorex and Pachycephalosaurus were the same species because they think that two pachycephalosaurids in the same environment would fill the same niche and therefore couldn't coexist unless they were the same.  Coming from the field of modern animal study, this is a completely weak argument, in my opinion.  One must only look at literally any ecosystem today to see that many related animals, sometimes within the same genus, co-exist.  The difference between two niches doesn't need to be something as drastic as skull shape.  It can be something as simple as a difference in mating season, odor, vocalizations or color (none of which can be preserved in the fossils we have).  I'm not saying this hypothesis is definitely false.  I'm saying we need more evidence to be sure, especially when dealing with just a few fossils from animals nobody has ever seen alive.

Regardless of what side you take, one must admit that Dracorex is a cool-looking dinosaur with a very cool name!

As always feel free to comment below or on our facebook page!  Also don't hesitate to request a prehistoric animal you would like to see me review and paint.  Just know that unless it's what I already have planned for the next two weeks (because it's my birthday month woot!) I won't review it until...at least two Sundays from now.

References

Bakker, R. T., Sullivan, R. M., Porter, V., Larson, P. and Saulsbury, S.J. (2006). "Dracorex hogwartsia, n. gen., n. sp., a spiked, flat-headed pachycephalosaurid dinosaur from the Upper Cretaceous Hell Creek Formation of South Dakota." in Lucas, S. G. and Sullivan, R. M., eds., Late Cretaceous vertebrates from the Western Interior. New Mexico Museum of Natural History and Science Bulletin 35, pp. 331–345. 

Sanders, Robert (30 October 2009). "New analyses of dinosaur growth may wipe out one-third of species". University of California at Berkeley. Retrieved 25 March 2010.

Erik Stokstad,"SOCIETY OF VERTEBRATE PALEONTOLOGY MEETING: Did Horny Young Dinosaurs Cause Illusion of Separate Species?", Science Vol. 18, 23 Nov. 2007, p. 1236; http://www.sciencemag.org/cgi/content/full/318/5854/1236^ ^{a b} Horner J.R. and Goodwin, M.B. (2009). "Extreme cranial ontogeny in the Upper Cretaceous Dinosaur Pachycephalosaurus." PLoS ONE, 4(10): e7626.