Dappershell
Split off from the Carapacer, the Dappershell took on a more pelagic habit and began to use its strong beak to consume nautstars. It is named for the fact that the "chestplate" part of its shell resembles a bow tie when viewed from below. To support its new pelagic habit, its lateral arms have become more flipper-like, its raptorial arm is reduced, and it has a bottom shell to protect it from attacks coming from below. It has also developed another new immediately visible characteristic—sexual dimorphism.
Unlike other lagnodactyls of the time, which lack any external sexual dimorphism, the Dappershell has sexually dimorphic anal arms. This serves to make mating easier, as well as allow Dappershells to more easily distinguish between males and females when looking for a mate to avoid wasting their genetic material. The male anal arm is longer while the female’s has reduced anal fingers, allowing them to easily fit together when the male assumes a mounting position over the female. The purpose of the mounting position is also to assist in successful mating; by holding onto the female with his lateral arms, the male has significantly lower risk of slipping. To keep a streamlined shape, the male will hold his anal arm flat against his underside while swimming, a bit like a terran crab.
The Dappershell’s digestive system is somewhat modified; to avoid digesting its entire melter detriti supply while trying to digest meat before it spoils, it has developed a “detriti pouch” where extra melter detritis in its gut can grow just in case. Though largely pelagic, the Dappershell typically needs to return to the seafloor to feed on crystal flora; with its slow reptile-like metabolism, however, it isn’t necessarily in any big hurry to do so and can still easily be found out in the open ocean far from any crystal flora.
Like its ancestor, the Dappershell lays eggs which hatch once the embryo has developed enough to form its shell. Dappershells cannot mate in open water, so their eggs are generally laid in the benthic parts of their range. Their offspring have little capability to obtain food on their own but require no parental care due to the persistence of their juvenile filter-feeding ability.