Diabloceratops, as mentioned yesterday, has a wicked looking set of horns on its face. Those horns were discovered in the original skull, which I think is the only skull discovered so far, and were almost entirely intact, which is an unusual feat in the arena of paleontology. The skull was found compressed, not crushed, with one side of the skull missing many key elements; the uncompressed side of the skull represented all of these elements well enough that a reconstruction was possible to create a full scale replica of the skull as it would have appeared in life, that is, non-compressed and in the correct living dimensions. The brow horns of Diabloceratops are unique amongst the majority of the centrosaurines not only because they exist, the vast majority of centrosaurine dinosaurs do not have actual horns above the brow ridges, but also because of the sheer size of those horns. Albertaceratops, another centrosaur, had brow horns as well (Greg Paul 2011 places Diabloceratops within the genus Albertosaurus), but the horns of Albertaceratops are slightly shorter than those of Diabloceratops. The frill horns of Diabloceratops are not abnormal, though, for the centrosaur family. Styracosaurus, for example, has a frill full of horns and is a contemporary of Diabloceratops, though is assumed to be slightly larger.
Walter Myers has been kind enough to show us the relative size of Diabloceratops compared to a living animal; the rhinoceros. Styracosaurus is a centrosaur that is a great deal larger, however, the frill of Diabloceratops almost makes the animal look just as big as its bigger cousin. This week, however, we are far more interested in Diabloceratops, so let us back away from Styracosaurus and Albertaceratops both and get back to Diabloceratops. The average white rhinoceros, that pictured, tops out at about 15 feet (4.6m) long and 6.6 feet (2m) tall weighing it at around 7,000lbs (3,500kg). As we can see with Mr. Myers illustration. To add in even more perspective, the horn of a white rhinoceros, perhaps this rhinoceros as well, averages approximately 35 inches (90cm) and can top out at 59 inches (150cm). This rhinoceros, assuming its average, shows by proxy that the horns of Diabloceratops' brow horns are approximately the same size as the nasal horn of the white rhinoceros and the frill horns are easily nearly double that size. Everyone can also easily observe, from both the illustration and the photographs of the replica skull, that there is no nasal horn present, that we know of, of course, present on the skull of Diabloceratops. Most centrosaurs present with nasal horns, with the exception of Diabloceratops (obviously), Alberaceratops, and Pachyrhinosaurus.