Styracosaurus albertensis

Lambe 1913

Evidence: A few skulls and skeletons, including bonebed remains.

Campanian

Dinosaur Park Formation

Alberta; Canada

Biology: 5.1 meters long – 1.8 tonnes

Because this dinosaur is known from mass graveyards in riverine deposits (Paul 2010; Weishampel et al. 2007), it is possible that they were herding animals. However, Rogers (1990) suggested that the congregational deaths might be due to incidental gatherings caused by drought. Although possibly more impressive than any other ceratopsian adornment, the elaborate horns and frills of Styracosaurus was probably used for the same purposes as other ceratopsian ornaments, such as display, rather than interspecific competition. Of course, the practical use of such lethal spikes as weapons seems evident, should the need arise. The Dinosaur Park Formation itself was host to a huge variety of dinosaurs, including several species of ankylosaurs, ceratopsians, and hadrosaurs. These animals may have competed for space and food with Styracosaurus albertensis. Predators to Styracosaurus may have included a few of the many species of deinonychosaurs that were present in the formation but, more than likely, it was much more concerned with tyrannosaurids. At least two species of these giant theropods could be found in the Dinosaur Park (Daspletosaurus and Albertosaurus) and the strong correlation between ceratopsian numbers and those of tyrannosaurids strongly indicates that the later preyed on the former.

Evolution

Styracosaurus albertensis was a defining member of the Centrosaurinae. Some have suggested that the genus was really just a synonym to Centrosaurus itself (Paul 2010) but this stance is not commonly accepted. Although the central nasal horn certainly equates Styracosaurus with Centrosaurus, its ring of horns around the frill seems to give it some distinction. I am of the opinion that this warrants it’s own genus, but demoting it to a subgenus is not at all out of the question.

References:

Paul, G.S. 2010. The Princeton Field Guide to Dinosaurs. Princeton University Press: Princeton, NJ.

Rogers, R.R. 1990. “Taphonomy of three dinosaur bone beds in the Upper Cretaceous Two Medicine Formation, northwestern Montana: Evidence for drought-related mortality.” PALAIOS 5(5): 394-341.

Dodson, P., C.A. Forster, and S.D. Sampson. 2007. “Ceratopsidae.” The Dinosauria, 2nd Edition. Weishampel, D.B., P. Dodson, and H. Osmólska (ed). University of California Press: Berkeley, CA. 494-513.