User blog comment:Lord Loss/Monster Hunter Theory... Blog/@comment-74.193.210.169-20120703025110/@comment-5020152-20120817144048

I think that the skulls are in fact prehistoric relatives of Monoblos/Gravios/Lao-Shan that were able to grow much bigger than their modern-day relatives.

For example: Meganeura and Carcharodon megalodon, both being much larger, but extinct, versions of modern day creatures (dragonflies and great white sharks).