👉 Craterostigmida is a type of crustacean that primarily inhabits freshwater habitats, including lakes and rivers. These craters are typically formed by the collapse or retreat of large bodies of water due to erosion, sedimentation, or other natural processes. Craterostigmida have a distinctive shell pattern known as "craterostigma," which is characterized by the presence of small, irregularly shaped depressions within their shells.