Old Earth Ministries Online Dinosaur Curriculum
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From Old Earth Ministries (We Believe in an Old Earth...and God!)
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Lesson 57 - Dracorex
Dracorex is a dinosaur genus of the family Pachycephalosauridae, from the Late Cretaceous of North America. The type (and only) species is Dracorex hogwartsia, meaning "dragon king of Hogwarts". It is known from one nearly complete skull (the holotype TCMI 2004.17.1), as well as four cervical vertebrae including the atlas, third, ninth and eighth. These were discovered in the Hell Creek Formation in South Dakota by three amateur paleontologists from Sioux City, Iowa. The skull was subsequently donated to the Children's Museum of Indianapolis for study in 2004, and was formally described by Bob Bakker and Robert Sullivan in 2006.
Length: 10 ft
Date Range: Late Cretaceous Period
However, Jack Horner et al. suspect that it is a juvenile Pachycephalosaurus. Now, a new analysis of pachycephalosaur fossils by a joint team from the University of California, Berkeley and the Museum of the Rockies has questioned the validity of two named genera of pachycephalosaur, Dracorex and Stygimoloch.
According to the team, specimens of Dracorex and Stygimoloch might actually represent earlier growth stages of Pachycephalosaurus. As this article on the UC Berkeley website says, "The confusion is traced to their bizarre head ornaments, ranging from shields and domes to horns and spikes, which changed dramatically with age and sexual maturity, making the heads of youngsters look very different from those of adults."
Dracorex, a herbivore, had a skull with spiky horns, bumps, and a long muzzle. The
In the Pachycephalosauridae, the Asian taxa includes a number of (somewhat) flat-headed pachycephalosaurs (Homalocephale calathocercos, Goyocephale lattimorei, and Wannanosaurus yansiensis). However, prior to the discovery of Dracorex, the only semi-flat-headed pachycephalosaur from North America was Stegoceras validum (inclusive of Ornatotholus browni). Even then, the semi-flat-headed trait was only present in juveniles of the species.
Aside from having a flat, nodal skull, the most prominent feature of Dracorex is the pair of huge and unrestricted superior temporal openings. The supratemporal fenestrae are much larger front-to-back and side-to-side than in Homalocephale, and larger than in Goyocephale. Only a fragmentary Wannanosaurus skull shows fenestrae as large as those of Dracorex. This fenestral architecture has been seen in ancient archosaurs, but not in other pachycephalosaurs.
Consequently, if unreduced superior fenestrae are morphologically primitive, then Dracorex is more primitive in the temporal region than any other known pachycephalosaur. However, Sullivan (2003, 2006) demonstrated that the oldest known pachycephalosaurs were, in fact, fully domed, and that the flat-headed morphology appeared later in the fossil record. This suggests that doming may be primitive for pachycephalosaurs and that a reversion to the non-domed, flat-headed state is a secondary (derived) character reversion, coupled with the re-opening of the supratemporal fenestrae. Indeed, while Stegoceras has been considered to be transitional between domed and flat-headed taxa, it may indicate the beginning of a character reversion to suppression of doming and opening of the supratemporal fenestrae in some taxa.
The excavated specimen was most likely a young adult. However, based on the beginning of ossification of the mid-cervical arch with the centrum, it was near maturity. The animal was approximately 10 feet (3 m) long.
Dracorex may actually be an individual of the closely related Stygimoloch and/or
The name Dracorex hogwartsia was inspired by young visitors to the Children's Museum of Indianapolis as a tribute to both dragons (Dracorex means "dragon king"), which the animal resembled, as well as the Harry Potter series of books by J.K. Rowling (hogwartsia for the Hogwarts School of Witchcraft and Wizardry, the fictional school from the popular series).
In Popular Culture
Dracorex is not very well known in popular culture but it has made an appearance in ITV's cult sci-fi drama Primeval, in which it escaped from the Cretaceous into medieval England. A knight mistook it for a dragon and tried to kill it, and even followed it into the present-day era, causing general chaos. However, Dracorex was depicted with exaggerated horns and a pair of fins along its back that are not found in the fossil record.
If you ordered the Test Pack, it is now time to take Test 8.
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