Thread:Animalman57/@comment-6025261-20180218074905/@comment-23825763-20180218220121

I personally think Stygimoloch and Dracorex are their own species. I know we have evidence of spikes smoothing out and becoming bumps in Triceratops, but I highly doubt that the skulls of these two could change in such a drastic way to become similar to the raised dome and no head spikes of a Pachycephalosaurus. I know Triceratops did change distinctly as it got older, but it didn't have a completly different facial structure for most of its life like these two would if they actually were Pachycephalosaurus. This also applies to Homalocephale and Goyocephalae who are also believed by some to be the same as Prenocephalae. I also think that they are completly different species, as, again, their skulls are completly different in structure from that of the supposed adult Prenocephale. Juvenile Prenocephale have even been found, which don't look like Homalocephalae or Goyocephalae, casting further doubt on the whole flat-skulled pachycephalosaurs are juveniles theory,