User blog comment:Lord Loss/Monster Hunter Theory... Blog/@comment-4687489-20120303150429/@comment-1011548-20120309075019

According to one of the MH encyclopedias, they are fairly closely related. But depending on whether you take that as gospel. Also, Gigginox CANNOT be 'an evolution' of Khezu because they both exist at the same time. Anyway, to me it just looks like a case of convergent evolution; the same habitat exists in two different geographical locations (cold caves) and two different species have both adapted to that habitat.