Eubrachyura is a group of decapod crustaceans comprising the more derived crabs. It is divided into two subsections, based on the position of the genital openings in the two sexes. In the Heterotremata, the openings are on the legs in the males, but on the sternum in females, while in the Thoracotremata, the openings are on the sternum in both sexes. This contrasts with the situation in other decapods, in which the genital openings are always on the legs. Heterotremata is the larger of the two groups, containing the species-rich superfamilies Xanthoidea and Pilumnoidea and all the freshwater crabs (Gecarcinucoidea, Potamoidea). The eubrachyura is well known for actively and constantly building its own burrows.
Source: Wikipedia
Heterotremata (Heterotrematan Crabs)
Superfamily Gecarcinucoidea
Family Gecarcinucidae (Southeast Asian Freshwater Crabs)
(Phuket, Thailand)
Superfamily Potamoidea (Old World Freshwater Crabs)
Family Potamidae (Eurasian Freshwater Crabs)
Subfamily Potamiscinae
(Kaeng Krachan NP, Thailand)
(Sabah, Malaysia)
(Sabah, Malaysia)
Superfamily Pseudothelphusoidea
Family Pseudothelphusidae (Neotropical Freshwater Crabs)
Subfamily Hypolobocerinae
(Milpe, Ecuador) 0F1A1855
Thoracotremata (Thoracotrematan Crabs)
Superfamily Grapsoidea (Land, Shore, and Marsh Crabs)
Family Gecarcinidae
(Bali, Indonesia)
(Bali, Indonesia)
(Christmas Island, Australia)
(Christmas Island, Australia)
Family Grapsidae
(Christmas Island, Australia)
Family Sesarmidae (Sesarmid Marsh Crabs)
(Sarawak, Malaysia)
(Phuket, Thailand)
(Phuket, Thailand)