What I actualy meant was, that the octigi's are the original species. From then Glocktigi evolved and from them came the Glukkons. OR, Glocktigi and Glukkons are two diffrent branches from the Octigi all together.
http://images.ea.com/eagames/officia.../bad/sekto.jpg
Just look, if some Octigi at some point mutated (chmical waste, nuclear accident, whatever) and two of it's tenticals grew longer (overtime becoming arms), and the Octigi's head growing even more (ever noticed the sort of 'bands' glukkons have running over the large part of their head), it's not an impossible theory.
I can't find any decent glocktigi pictures anywhere to write a theory about, so I'l leave that to Xavier and his 1337 picture finding skillz :P.