Bit of clarification: Xenacoelomorpha is the phylum that the genus Xenoturbella is under.

Someone left a tag at the top of the Xenacoelomorpha article advocating a rewrite, which I could probably quickly investigate right now (or even just check WoRMS) if I weren’t currently a lazy lump of dead weight. Without assessing the tag’s merits, I’d at least advise treading lightly as a heuristic.