Evolved from the bottom dwelling torquatocauda flabellum, s. primus is the first segmented creature of its kind (excluding the binucleusdetritivorus worm). Having lost its 'tailfins' it undulates through the silt on the seabed sifting debris (it has also evolved a tubular structure, to allow particles to flow through). Being segmented offers an advantage to growth and reproduction: s. primus can grow indefinitely by simply adding segments. Very long specimens simply shed segments to reproduce, which crawl away autonomously to grow some more. Large specimens have been known to reach up to a centimeter in length, although they are extremely slender thin and prone to breaking up into several smaller creatures. Due to lack of predation s. primus has become extremely abundant on the seabed.