Platyprotus phyllosoma, gen. nov and sp. nov., from Enderby Land, Antarctica, an unusual munnopsidid without natatory pereopods (Crustacea: Isopoda: Asellota)

Abstract

New genera and species, Platyprotus phyllosoma, of munnopsidid isopod are described from Enderby Land, Antarctica. Platyprotus differs from all other munnopsidids, except Microprotus Richardson, 1910 and some species in Storthyngurella Malyutina, 1999, in having fully ambulatory periopods 5-7 without natatory setae. Platyprotus differs from those genera primarily in body shape, lack of marginal spines on pereonites 5-7 and pleotelson, lack of a pre-anal ridge, and in possessing highly derived spatulate setae on article 3 of the mandibular palp. All three genera are part of a wider Storthyngura clade. If the present concept of Storthyngurella is confirmed, ambulatory pereopods 5-7 have been derived independently more than once within the clade. The family name is emended to Munnospididae Hansen, 1916.