Phylum Radiolaria Müller, 1858 see Subphylum Radiozoa Cavalier-Smith, 1987
   Superclass Polycystina Ehrenberg, 1838 see Superclass Polycystinia Ehrenberg, 1838
     Class Stauraxonaria Afanasieva & Amon, 2005
       Order Spongodiscata Haeckel, 1862
         Family Coccodiscidae Haeckel, 1862
           Subfamily Coccodiscinae Haeckel, 1862
             Genus Trigonactum Afanasieva & Amon, 2005, nom. null. see Genus Trigonactura Haeckel, 1881