Remipedia

Remipedes are a class of crustaceans that are considered primitive and have adaptations for cave dwelling. The term "remiped" describes crustaceans or insects that have legs used as oars.12

The appendages of crustaceans, including remipedes, are thought to have evolved from a double-branched limb structure. These limbs typically have a basal part with an inner and outer branch. The specific arrangement and form of these appendages are key to distinguishing different crustacean groups. The study of crustacean evolution involves examining both comparative anatomy and the fossil record, though the earliest fossil crustaceans are already specialized.31