Borewurm

The Borewurm has split from its ancestor and returned to the water table. On its way, it picked up strange new adaptations that helps it survive in the water table's rocky interior. The most notable of which is its fayalite exoskeleton, which is produced from the broken-down remains of the basalt the borewurm consumes. This is made possible by the borewurm's new chemeba symbiont, which breaks down the basalt into its basic components, leaving the borewurm with SiO4, Fe2+, Al3+, and Mg2+. While the SiO4 and Fe2+ is used to form its fayalite exoskeleton, the Mg2+ and Al3+ is excreted as a waste product as oxides due to the borewurm not being able to use it. This causes the borewurm's tunnels to be filled with magnesium and aluminum oxide deposits. Because the hardness of fayalite exceeds the hardness of basalt, the borewurm is able to bore through solid rock. This is achieved through a modified form of its ancestor's sucker. This radula-covered digging apparatus is effectively a sheath of muscle coated in thick flesh and fayalite radula. The borewurm digs by pulling the sheath in and out of its mouth, causing the radula to scrape against the basalt in front of it, grinding it down in the process. The thick flesh of the sheath helps protect it from being damaged by shards of basalt. However, in spite of its amazing digging abilities, the borewurm prefers to dig through soils than solid rock, as doing the latter is energy-intensive. The borewurm derives its main source of carbon from the rhizoids of Table Cushions and Villigrass. In spite of their redundance, the gut majurums that inhabit the borewurm's gut can still be of use when the borewurm consumes villigrass rhizoids, as the presence of gut majurms allows the borewurm to convert the rhizoids' Fe3+ into Fe2+. This allows it to use the iron gained from villigrass in the formation of its fayalite exoskeleton.