Wikipedia
Thermosbaenacea
Thermosbaenacea is a group of crustaceans that live in thermal springs in fresh water, brackish water and anchialine habitats. They have occasionally been treated as a distinct superorder (Pancarida), but are generally considered to belong to the Peracarida. Due to their troglobitic lifestyle, thermosbaenaceans lack visual pigments and are therefore blind.
The current distribution of some genera tallies well with the Miocene extent of the Tethys Sea, and it is assumed that the extant taxa are derived from ancestors that lived in open marine habitats. Elsewhere, the distribution is consistent with the break-up of Pangaea.
The developing embryos are carried by the adult under its carapace until hatching.