Scytheworm
The Scytheworm has split from its ancestor and grown over 6 times larger, taking advantage of the ever-increasing number of prey items. Most notably, its antennae have developed large curved, flat-bladed projections, giving it its name. The 'scythes' can be swung with impressive force and have moved downwards on the organism's head to allow them to be swung horizontally forward. Using these new implements, the worm can detach Longarm Pseudosinias from their holdfasts and consume them using its smaller mouth-limbs, which grip food and insert it into its mouth. The antennae are very strong and the blades, similar to the clubs of an Earth mantis shrimp, are covered in a highly mineralised outer layer with extreme rigidity, followed by layers upon layers of rotated, softer material beneath.
The scythes are also useful in defense, as the worm can use them to fend off its only true predator, the Devorator. Its antenna can swing the blades with enough force to slice off tentacles and damage the Devorator's armor and so the creature has had to develop its UV bulbs to help determine which direction the worms will be facing in order to safely approach from behind.
Additionally, the worm has 10 small legs to help it move along the seafloor.