STL Science Center

STL Science Center

05 October 2013

Exaggerating the Exaggerated

©Lukas Panzarin
The horns of Nasutoceratops are a very interesting and important subject to cover when discussing this dinosaur. There are a variety of reasons why the horns of any given ceratopsian are important. This dinosaur's horns, however, are important because their design is rather unique and, coupled with the bulbous sinus cavity of this particular Centrosaurine ceratopsian represent apomorphies of the dinosaur and can be used to diagnose the position of the dinosaur within the subfamily. The horns appear slightly exaggerated, and they are to a point, but these coupled with the unadorned parietal frill and the enlarged sinus all point to a position within the family that is in the medially basal part of the phylogenetic tree. The Centrosaurine phylogenetic tree basally exhibits characters that include vaguely ornamented parietal-squamosal frills combined with medium to large brow horns and a low nasal ridge or small nasal horn. The more advanced members of the family lose brow horns entirely and have ornamented frills with thick nasal bosses and ridges along the parietal.

The parietal frill's ornamentations are, simply put, very weak compared to the ornamentations of later members of the family like Styracosaurus. The brow horns' cores are slightly smaller than those of even more basal forms, such as Diabloceratops. The nasal ridge is quite prominent in Nasutoceratops and the sinus cavity is enlarged, as stated previously. The antorbital fenestra is not exactly larger than any other Ceratopsian or Centrosaurine specifically, but evidence for the extension of the sinus cavity extending along the nasal and top of the maxilla  has been described briefly at least. An enlarged olfactory and sinus may provide us with what was essentially the first truffle scenting animal. Picture that for a moment as you look at this skull with its extremely forward pointing and almost horizontal brow horns; a truffle digging ceratopsian. That idea is one part speculation and two parts hopeful interpretation of what we are looking at on my part, however, and is not, to my knowledge endorsed by anyone else.

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