The Terrestrial Isopod Genus Ischioscia in Costa Rica: New Species and Records, and an Analysis of its Phylogeny (Crustacea, Isopoda, Oniscidea)

Abstract

Examination of the Isopoda collection of the Museum de la Universidad de Costa Rica revealed new information on the Oniscidea of Central America. Besides representatives of the genus Venezillo Verhoeff, 1933 (Armadillidae), the “philosciid” genus Ischioscia Verhoeff, 1928 is the most important taxon in Costa Rica. The presence of seven species of Ischioscia Verhoeff, 1928 in the fauna of Costa Rica is somewhat surprising, since in other parts of the Neotropics fewer species are known to coexist. Previously, in Costa Rica three species were found: Ischioscia martinae Leistikow, 1997, I. muelleri Leistikow, 1997 and I. elongata Leistikow, 1997, and new records are presented for these species. In addition, four species new to science are described and figured in detail: I. cadoangelis sp. n., I. plurimaculata sp. n., I. quadrispinis sp. n. and I. marmorata sp. n. A key to the Costa Rican species is given and the phylogenetic relationships of the genus and the Costa Rican species is discussed.