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 Pyloniata Haeckel, 1881
Superfamily Larnacillioidea Haeckel, 1887
Family Larnacillidae Haeckel, 1887
Subfamily †Histriastrinae Dumitrica, 1989
Genus †Stephanastrum Ehrenberg, 1847