User blog comment:Kogath/Monster Hunter 4 Ultimate for the Nintendo 3DS/@comment-21371438-20140713084151/@comment-5582528-20140713172201

Strictly speaking, pseudowyvern IS a canon taxonomical term for the superfamily containing nargacugas and barioths, of which tigrex isn't a member of (he's in a different branch that also contains Akantor and Ukanlos)