|An alternative without the "tear" in the frill is equally viable|
for the same reasons
One person I am very anxious to get a hold of, and have been for quite a while now, has been Keiji Terakoshi. One of the reasons is to get official permission from him to use his artwork, the other being to congratulate him on his publications like this book sample below. While it is all in Japanese it puts all three of our questioned species, for today at least, together in one simple and easy place. Monoclonius is pictured at the top of the picture while Styracosaurus and Centrosaurus appear in the center and right on the bottom, respectively. Styracosaurus juvenile, we can see, is a little more of a stretch as it would require a considerable growth spurt in the frill. While not something that is not to be excluded from thought, it is not as probable as the growth of the Centrosaur frill. However, Peter Dodson has in the past put forth the idea that Monoclonius may have been a Styracosaurus gender role, being the female of the gender. This lack of ornamentation in females is seen all over the extant animal world in birds especially, but also in mammals and reptiles and fish as well. This is an interesting debate, and I hope to see some good evidence from the "professionals" as I continue to research so I can share it with you.