Megaorthoceros Sessilia

Megaorthoceros sessilia are a giant descendant of megaorthoceros segnoneustes. Because of their new lifestyle, they have not replaced their ancestors. Females grow to an overall length of 1 millimeter in length, from the tip of their flagellum to the tip of their proboscis.

Males have still not changed in overall size, although they now will not feed; instead, each female will birth a small "puff" of males, who will proceed to "pollinate" other local females. A week later, new females will begin budding. Juvenile females still look very similar to M. segnoneustes, but they will quickly locate a location upon which to anchor themselves semi-permanently, which they do so by fusing their flagellum to the substrate. More often than not, they will be found on rocks (where large colonies may form) or larger pieces of sediment (where they will appear more spread out); however, it is not unheard of for them to attach to living organisms, although this isn't done on purpose. Not even effulgent scylarians are necessarily safe from this occurrence, although the sessilia won't cause any actual harm to the individual organism.

Should a storm ravage the local habitat, the females can detach their flagellum from their location to "set up shop" elsewhere, although this is more likely to occur in the groups attached to larger sediment than the other two group types.

Because females have grown so large, they are now visible to the naked eye, albeit barely, and since most of this length is their flagellum and their proboscis, their actual body is still pretty much microscopic. Their paddles are still used to control their movements to get to a location to anchor themselves, but afterward they are used to try and sweep waters towards themselves to increase their feeding potential. Any and all microbes are potential food for them, although males of their own species are never eaten because the male will simply attach itself permanently into the female's proboscis, becoming little more than a lump of cytoplasm, offering up its own DNA when the time calls for it.