User blog comment:Mckrongs/Monster Hunter 4 for the Nintendo 3DS/@comment-9083744-20130503234356/@comment-1758220-20130507185311

If that was the case then why even call it a wyvern at all? And I'm sure capcom was aware of the mythology too, seeing as the very first monsters in the series to be classified as Wyverns actually looked like Wyverns. What if I made a game and had a class of monsters in it called Canines, most of which were large dog monsters, as expected. Then I added in a wyvern monster that looked exactly like Rathalos in every way, and just classified it as a "Flying Canine" even though it has absolutely zero characteristics of a dog-like monster at all. That is basically exactly what they're doing here.

Hell, even Leviathans are called Wyverns by their titles and in-game pseudonyms. Capcom basically has no filter at all, and they pretty much just classify and large monster that isn't 100% mammalian as a wyvern.