User blog comment:Kogath/Monster Hunter 4 Ultimate for the Nintendo 3DS/@comment-24897922-20140503192720/@comment-4212769-20140504151339

Well, Zinogre appears in the Deserted Island, the Moga Woods, so he has a place in MH3U. Also Zinogre is a flagship of 3rd gen, would be weird to have him out of MH3U.

MHP3rd just took all the available monsters from MH3 that aren't too water based without further ado. Only the monsters that are the most of the time in water were left out for obvious reason.

Again with Tigrex, as MH4U has the story of MH4 with further story elements for being an expansion Tigrex simply has to return.

I don't know what happened to Bulldrome and Akantor/Ukanlos. lol While I can assume a good reasoning for Akantor and Ukanlos, I have the feeling they simply forgot Bulldrome. XD