With no competition except inter-specie competition in the empty post-disaster Ittiz-Nuke Alpine the tube fessurum replaced its ancestor. They became twice as big. With the only natural pressure being competition over iron-deposits and rock slides killing the unprotected and unlucky its main adaptations are a harder iron-shell, greater size, and a couple of tube arms. These tube arms replaced the former small drilling limbs to become more efficient at draining iron from underneath the soil. They also now filter-feed microorganisms in the dirt and use them as a source for their organic parts, which allowed them to grow much larger. They also evolved wider legs for better movement in the rigid mountains. Finally they still reproduce using fragmentation, spawning a single offspring about once in a few months. The offspring grows out of a bulb that grows where their tail once was.