This is the eyed flyworm. This worm replaced its ancestor when a mutation which brought back its ancestor's long-lost ability to see, except this time instead of being on the back of the creature, it was on the sides. This mutation gave it the ability to group together better, so that they could create large swarms. It also gave them the ability to flee from danger when their olfactory senses would otherwise be useless (when they are buried in a carcass, feces, etc.).
These advancements allowed it to expand their territory to the extreme, covering all of Wright (except the Alpine, where it is too cold for the worms, and some of the caves, where they would not be able to gain any nourishment). The eyed flyworm is the same as its ancestor in all other respects.
Living Relatives (click to show/hide)
These are randomly selected, and organized from lowest to highest shared taxon. (This may correspond to similarity more than actual relation)