STL Science Center

STL Science Center

03 May 2013

The Great White North

©Nobu Tamura
It seems that we spend a lot of time in Canada. Not as much recently, even though we have discussed two animals from Canada in the past three weeks if you count this upcoming week. Conveniently, since I may potentially discuss them this evening, we are talking about Albertaceratops. Albertaceratops nesmoi was named after Alberta and the rancher that helped get the skull and skeleton of Albertaceratops out of the ground (a guy named Cecil Nesmo). When it was discovered, in 2001, and originally described it was considered the most basal centrosaur that had been found to date. It possessed a highly centrosaurine aspect to the actual skull but retained rather large supraorbital (or eyebrow) horns. The problem this posed is that it was rather peculiar; other centrosaurs lack these supraorbital horns, replacing them with small nodules or bony plates, entirely while maintaining ornamented frills and small nasal horns or bony plates. A centrosaur skull had never been found with impressive horns like these above the eyes; we have discussed one later discovered centrosaur that did have this type of horns though. The approximate weight and size have not, to my knowledge, been estimated but the age of the fossils places these animals as having lived approximately 77.5 million years ago. As basal centrosaurs, and with a good handful of species following, that means that the centrosaurs were a fairly short lived line in terms of dinosaur clades.

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