A new epigean species of Trichoniscoides (Isopoda: Oniscidea: Trichoniscidae) from the northwest of the Iberian Peninsula

Abstract The genus Trichoniscoides Sars, 1899 is composed mostly of cave-dwelling species. In the Iberian Peninsula, 32 species, and three additional species of uncertain status (partially described but not named), are currently known to occur. We were able to study one of these unnamed species, clarify its status, and name it. Most of the Iberian species of this genus are troglobiotic (22) and the ten remaining are epigean or troglophilic. The description of the new species from the surface can help in understanding the variability observed in the troglobitic species. The new, formally described, species has morphological characteristics that fit in several currently proposed groups for the genus, therefore, it is not possible to attribute Trichoniscoides gallaecus n. sp. to any of them.