Centrosaurus

Credit: Fred Wierum.

*Centrosaurus* is an extinct genus of centrosaur that lived in North America during the Late Cretaceous.

## Description

The stocky bodies of *Centrosaurus* were supported by pillar-like legs, although they were not very large in comparison to others. These animals bore the signature horn on their snouts, which curved forwards or back depending on the individual. Cranial ornaments reduced as the dinosaur aged. The frill was relatively short, being about half the skulls length, 68.8 centimeters in the eldest and largest specimens. The genus is distinguished by two forward-curving Hornets at the top of the frill. Two small upwards-stretching horns above the eyes. The frill has large fenestrae and osteoderms lining its sides. Skin impressions of Centrosaurus are known.

## Paleobiology

Like many ceratopsians, *Centrosaurus*' jaws were built to shear plants. Bonebeds of *Centrosaurus* suggest they are gregarious animals. These beds are located in Canada, and one notable Dinosaur Park Formation preserve *Centrosaurus* and *Styracosaurus* remains. The mass deaths may have been caused by non-herding animals gathering around a waterhole during a drought. Centrosaurus is found in lower deposits while *Styracosaurus* is found higher, meaning that *Centrosaurus* was displaced by *Styracosaurus* populations as time went on.

Ceratopsian ornamentation is among the most distinct type in dinosaurs. Lesions and injuries in ceratopsians are most commonly caused by intraspecific combat among themselves, in a study examining *Triceratops* and *Centrosaurus* frill injuries. The fenestrae in *Centrosaurus* are not built to withstand predator attacks, unlike the solid frills of *Triceratops*. *Centrosaurus* frills likely developed for species recognition, display or both.

### Paleopathologies

A specimen of *C. apertus* from Dinosaur Provincial park suggests osteosarcoma in the right fibula. Analysis of the cancerous legions suggest the cancer had began to enter an aggressive stage. This would have produced a major limp and increased vulnerability to predation. However, the herd mentality of the dinosaur suggests it could have survived longer than expected alone. The individual is thought to have actually drowned in a flash flood, which produces such bonebeds. This individual is one of the few dinosaurs that preserve severe cancer in their bones.

## Paleoecology

Thomas M. Lehman noticed that *Centrosaurus* have not been found outside southern Alberta, though they are the most abundant Judithian dinosaurs. Large North America Late Cretaceous ceratopsians are known to have relatively small geographical ranges, despite their sizes and mobility. This restricted region contrasts with large herbivorous mammals, that typically span entire continents.

## Classification

In Gregory S. Paul's (2010) Princeton Field Guide to Dinosaurs, he synonymizes most typical centrosaurines intro *Centrosaurus*, transferring their epithets. For example, *Styracosaurus* is referred to as *C. albertensis*. Due to errors in the text and the unconventional taxonomy Paul leads this mass synonymization to be discredited.

## Species

### Reassigned Species

* *"C." albertensis*
* *"C." brinkmani*
* *"C." nasicornis (lapsus)/nasicornus*
* *"C." sternbergorum*
* *"C." ovatus*
* *"C." procurvicornis*
* *"C." horneri*
* *"C." lakustai*
* *"C." canadensis*
* *"C." perotorum*

## Synonyms

* *Eucentrosaurus*
* *C. flexus*
* *Monoclonius nasicornus*
* *Monoclonius dawsoni*
* *Monoclonius longirostris*
* *Monoclonius cutleri*

## Gallery

Various *Centrosaurus* parts at the Royal Tyrrell Museum.Cast of AMNH 5427 at the Museum of Victoria.*Gorgosaurus* and *Centrosaurus* at the Royal Tyrrell Museum.*Styracosaurus*, *Wendiceratops* and *Centrosaurus* frills at the Royal Ontario Museum.
**Credit: Clumsystiggy on DeviantArt.***Centrosaurus* skull at the Royal Ontario Museum.
**Credit: Clumsystiggy on DeviantArt.**
## References

* https://en.wikipedia.org/wiki/Centrosaurus
* https://blogs.scientificamerican.com/tetrapod-zoology/greg-pauls-dinosaurs-a-field-guide/
* https://archive.org/details/g.s.paul2016theprincetonfieldguidetodinosaurs/page/n253/mode/1up