Diabloceratops

Diabloceratops ( ) is an extinct genus of centrosaurine ceratopsian dinosaur that lived approximately 81.4-81 million years ago during the latter part of the Cretaceous Period in what is now Utah, in the United States. Diabloceratops was a medium-sized, moderately built, ground-dwelling, quadrupedal herbivore, that could grow up to an estimated in length and in body mass. At the time of its discovery, it was the oldest-known ceratopsid, and first centrosaurine known from latitudes south of the U.S. state of Montana. The generic name Diabloceratops means "devil-horned face", coming from Diablo, Spanish for "devil", and ceratops, Latinized Greek for "horned face". The specific name honors Jeffrey Eaton, a paleontologist at Weber State University and long time friend of the lead author Jim Kirkland. Eaton had a big role in establishing the Grand Staircase-Escalante National Monument where the specimen was found. The type species, Diabloceratops eatoni, was named and described in 2010 by James Ian Kirkland and Donald DeBlieux.

==Discovery== thumb|left|Preserved fossil material of specimen UMNH VP 16704 thumb|Holotype skull of Diabloceratops The only specimen of Diabloceratops eatoni was recovered at the Last Chance Creek Member of the Wahweap Formation, in Kane County, Utah. Type specimen UMNH VP 16699 was collected by Don DeBlieux in 2002, at the Last Chance Creek locality of this formation, in intraclastic sandstone that was deposited during the Campanian stage of the Cretaceous period. The stratigraphic level of which it was found has been estimated to be 81.27 Ma, with an error range between 81.42 and 81.01 Ma. It consists of a partial skull with a piece of the lower jaw, with the right side being intact and part of the left side, which has been weathered. Another specimen, UMNH VP 16704, was discovered years earlier in 1998 by Joshua A. Smith of the same formation, but was not described until 2010, when it was assigned to Diabloceratops. However, this specimen may not belong to Diabloceratops, because it shares features found only in more derived centrosaurines. Some researchers suggest that the UMNH VP 16704 specimen is more similar to Machairoceratops, Yehuecauhceratops and Menefeeceratops than to Diabloceratops due to the fan-shaped shape end of the squamosal. These specimens are housed in the collection of the Natural History Museum of Utah.