Phylum Gnathostomulida Ax, 1956 - gnathostomulids Order Bursovaginoidea Sterrer, 1972 Suborder Scleroperalia Sterrer, 1972 Family Gnathostomulidae Sterrer, 1972 Genus Corculognathia Ehlers & Ehlers, 1973 Genus Gnathostomula Ax, 1956 Genus Semaeognathia Riedl, 1970