User blog comment:Jamintheinfinite/Subnautica Creature Evolution/@comment-28450065-20180323194412

Reefbacks being related to Gasopods is not likely. The data bank states that the resemblances between the two are purely visual, the glands themselves are for a completely purpose. There's also the fact that the Reefback is an invertebrate whilst the Gasopod clearly is not.

The Rabbit Ray also splits off from the Alpha Ray rather than the Ghostray.

The Boneshark, Biter, Sand Shark, Rockgrub and Theta also don't fit like that. The five of them should all be splitting from one common ancestor. Rather than the other four splitting from the Theta.

Aside from that I think everything else looks quite accurate.