URSTYLIDAE, Riehl & Wilson & Malyutina, 2014

Riehl, Torben, Wilson, George D. F. & Malyutina, Marina V., 2014, Urstylidae - a new family of abyssal isopods (Crustacea: Asellota) and its phylogenetic implications, Zoological Journal of the Linnean Society 170 (2), pp. 245-296 : 287

KEY TO THE SPECIES OF URSTYLIDAE

1. Body without sternal spines, (females) not keeled; pereonite 4 posterolateral margins rounded, with simple setae; pereonite 6 posterolateral margins produced posteriorly, rounded; pleotelson rather stout (L/W <1.5), with anterior and posterior convex outline separated by concave waist; pereopod I positioned ventrally and orientated anteriorly, ischium dorsal margin projecting near basal width of segment..................................................................2

– Body with sternal spines, partly keeled; pereonite 4 posterolateral margins acutely tapering, with robust, spine-like setae; pereonite 6 posterolateral margins not produced; pleotelson elongate (L/W> 1.5), subrectangular, waist only weakly pronounced, lateral margins subparallel; pereopod I positioned lateroventrally and orientated dorsolaterally, ischium dorsal margin projection much greater than basal width of segment........ Urstylis thiotyntlus sp. nov.

2. Body subcylindrical; pereonite 7 without posterolateral protrusions; pereopod VII shorter than pereopod VI; operculum with lateral setal fringe absent........................................................... Urstylis zapiola sp. nov.

– Body dorsoventrally flattened; pereonite 7 with posterolateral protrusions similar to pereonite 6; pereopod VII length subsimilar pereopod VI length; operculum with lateral setal fringe present ... Urstylis solicopia sp. nov.