User blog comment:Lord Loss/Monster Hunter Theory... Blog/@comment-5963861-20130927031528/@comment-6005381-20131007155753

earth's atmosphere is not dense enougth, as well as it's gravity being too strong for many of the monsters to fly or even exist. that was determined ages ago, and probably should be added to the generally acepted theorys, along with quite a few other things. The monsters similar to earth animals all have unique differances to the earth versions so there not the same.