The hypogean Paranthuridae Cruregens Chilton and Curassanthura Kensley (Crustacea, Isopoda), with remarks on their morphology and adaptations

The morphology of the only two known hypogean Paranthuridae ( Cruregens fontanus Chilton, 1881; Curassanthura halma Kensley, 1981) is described. Curassanthura has no closely related marine relatives and must be placed at the base of the more specialized Paranthuridae; Cruregens is closely related to the specialized genus Colanthura, which lives in the upper littoral. Comparing the hypogean paranthurids with Colanthura, several analogies can be found in the hypogean species (body slender, only P 1 with stout subchela, P 4-6 slender, P 7 missing, uropods slender or short and bearing long setae), which can be explained from the way of living of the Paranthuridae.