Prying Horrorstar
The prying horrorstar develops from horrorstars that spread east into the Wright's shallow seas, where the wormstem and its descendants thrived. It has specialized to live among thickets of wormstems and wormreef reefs, and it preys on them as well.
To eat these worms, it uses the prying action that gives it its name. The mobile spikes on either side of the mouth are longer, and it inserts one into a gap between its prey's segments, then pries it off to expose the soft core. It eats these the same way horrorstar eats: the spikes hold the food as the mouth inverts into a stomach, sucking it in.
They make much use of their raptorial arm when feeding as well. They can pick up their food and grip it while they're prying. Because wormreef mostly consists of a heap of polyps, they can just grab an individual polyp and remove it from the reef. They can also pick up juveniles as they're crawling along the sea floor, taking advantage of their better mobility as swimmers.
The prying horrorstar's body shape has adapted to a lifestyle in which maneuverability is more important than speed. They swim in shallows thick with wormstems and wormreefs, rather than venturing for long periods in open waters. They have a rounded tailfin (horizontal, like its ancestor) and a more compressed body.
Otherwise, its structure and interior are much like its ancestor, with an internal pelvis of cartilage attached to its mouthparts, pigment cup eyes, and gills lined by modified baits. It also reproduces by clasping anal arms together (the fin retracts), bearing live young that begin life as radial larvae.