[Happy Monkey]

All Earth vertebrates come from an animal with four limbs. The only group that I can think of that doesn't have them anymore is snakes. What bugged me evolution-wise is that the Na'vi didn't have any of the features that the other creatures had (except the brain-tentacles). I guess they're Pandora's version of snakes, except in addition to missing limbs, they lost eyes and breathing-holes too.