Centrosaurus

Centrosaurus apertus is the type species of the genus Centrosaurus, which gives its name to the subfamily Centrosaurinae. This dinosaur is known from an extraordinary number of fossils. It is perhaps the most abundant ceratopsian in the fossil record, surpassed only by Triceratops. In the Dinosaur Park Formation of Alberta, researchers have discovered mega-bonebeds containing thousands of individuals at single locations.

As a moderate-sized centrosaurine, it possessed a single tall nasal horn, which was smaller than that of Styracosaurus. It also had small brow bumps instead of horns. Its parietal frill featured two large, hooked processes that curved forward over the top. The specific shape and arrangement of these hooks distinguish Centrosaurus from its close relatives. Like other ceratopsids, it had a parrot-like beak, complex dental batteries, fleshy cheeks, and a robust quadrupedal stance.

Mega-bonebeds like Bonebed BB 43 at Hilda, Alberta, preserve at least 1,000 individuals in one spot, representing the largest known ceratopsian aggregation. Paleontologists believe these sites resulted from mass-drowning events during river crossings. This suggests that Centrosaurus lived in massive herds, possibly the largest of any North American horned dinosaur. Since these bonebeds contain individuals of various ages, they may indicate seasonal gatherings for breeding or migration rather than permanent mega-herds.

The animal's frill ornaments, especially the forward-curving hooks, likely served as display features for species recognition. While they could have been used in combat, this was probably a secondary function. Biomechanical analysis of its skull and teeth indicates that Centrosaurus fed on tough, fibrous plants such as ferns, cycads, and conifers.

• NMC 348 — Lambe's holotype, Canadian Museum of Nature.
• Hilda Mega-Bonebed (BB 43) — Royal Tyrrell Museum and University of Alberta; estimated >1000 individuals.
• Multiple Dinosaur Park Formation specimens at Royal Tyrrell, ROM, AMNH.

Genus and species count — C. apertus is well-defined. Previously named species are now placed in other genera (notably Coronosaurus brinkmani, formerly Centrosaurus brinkmani). Frill function — display + species recognition; combat secondary. Bonebed taphonomy — mass-drowning during river crossing is the dominant interpretation but specific mechanisms debated.

Centrosaurus is less famous than Triceratops but features in many recent dinosaur productions including Walking with Dinosaurs: The 3D Movie (2013) and Prehistoric Planet (2022). The Hilda mega-bonebed has been featured in numerous popular-science articles on dinosaur herd behaviour.

• ceratopsia
• styracosaurus
• pachyrhinosaurus
• triceratops

• Lambe, L. M. (1904). On the squamoso-parietal crest of two species of horned dinosaurs from the Cretaceous of Alberta. Ottawa Naturalist, 18, 81–84.
• Ryan, M. J., Eberth, D. A., Brinkman, D. B., Currie, P. J., & Tanke, D. H. (2007). A new pachyrhinosaur-like ceratopsid from the Late Campanian of Alberta. PaleoBios, 27, 1–18.
• Eberth, D. A., et al. (2010). A bonebed database for centrosaurine ceratopsids of the Belly River Group of Alberta. PalAss Conference Abstracts.
• Dodson, P. (1996). The Horned Dinosaurs. Princeton University Press.