She decapod crustagh y phartan. T'ee ny h-olteyr jeh'n mynoardagh Brachyura, as famman feer ghiare eck (βραχύ/brachy = giare, ουρά/oura = famman), ny ny keayrtyn, ta'n clane brooinney cloagit fo y thoraks. Ta ushylagh mooie çhiu ec y chooid smoo jeu, as jees dy h-igney oc. Ta fys ayn er ny smoo na 6,700 dooie.