In Depth
Proceratosaurus was a small predatory theropod dinosaur active in what would become southern England during the mid-Jurassic. Arthur Smith Woodward first described the partial skull of Proceratosaurus as another species of Megalosaurus, a genus that suffered from the wastebasket taxon effect of almost any predatory dinosaur fossil being attributed to it. Friedrich von Huene split the skull from Megalosaurus and gave it its current name due to the nasal horn that was similar to the better preserved Ceratosaurus from North America. Proceratosaurus was thought to have been the ancestor to Ceratosaurus, and both were placed within the Coelurosauria group.
The above held true until the realisation that Ceratosaurus was not a member of the Coelurosauria in 1980. This immediately meant that Proceratosaurus could not be the ancestor to Ceratosaurus because of its own coelurosaurian features. The discovery also resulted in Proceratosaurus being looked at again to see if is really should be placed within the Coelurosauria.
Initially Proceratosaurus had an uncertain position and was briefly considered as a primitive allosaurid. However further studies would continue, resulting in Proceratosaurus being tentatively placed within the Coelurosauria in 2004 by Thomas R. Holtz, Jr. However a further study in 2010 by Oliver Rauhat et al. would have even further implications for the future of Proceratosaurus. Not only was Proceratosaurus confirmed as a coelurosaurid, it was even identified as a tyrannosaurid, something that resulted in the creation of the Proceratosauridae. This is the family group that sits within the Tyrannosauroidea and includes all theropods closer to Proceratosaurus than Tyrannosaurus.
Although some have questioned the above lineage, if it is correct then Proceratosaurus, or a dinosaur very much like it, would go down as the distant ancestor to the tyrannosaurids instead of other dinosaurs such as Guanlong and Stokesosaurus which previously held the title. To clarify matters this would mean that Proceratosaurus was the dinosaur that would go on to produce the giant tyrannosaurid predators of the late Cretaceous including,Daspletosaurus, Alioramus, Yutyrannus Gorgosaurus, and most famous of all, Tyrannosaurus.
Further Reading
– On several known and unknown reptiles of the order Saurischia from England and France. – Annals and Magazine of Natural History, series 9 17:473-489. – F. von Huene – 1926. – Cranial osteology and phylogenetic position of the theropod dinosaur Proceratosaurus bradleyi (Woodward, 1910) from the Middle Jurassic of England. – Zoological Journal of the Linnean Society. – O. W. M. rauhut, A. C. Milner & S. Moore-Fay – 2010.
