[QUOTE=OANST;366914]Ahhhh, people taking the evolutionary process of fictional creatures seriously! Stop it! Stop it! Stop it!
No! We refuse!! (Snarl)
If anything, you could say that all the species on Oddworld are vertebrates (well, except for Octigi). Of course, here I am assuming that Octigi are made of all cartilage like octopus, but maybe they do have the beginning of a vertebrate, it just isn't as developed as that of the Glukkons. Comes from living a primitive life aquatic, I guess.