Phylum Gnathostomulida Ax, 1956 - gnathostomulids Order Bursovaginoidea Sterrer, 1972 Suborder Scleroperalia Sterrer, 1972 Family Clausognathiidae Sterrer, 1992 Genus Clausognathia Sterrer, 1992 Clausognathia suicauda Sterrer, 1992