Phylum Porifera Grant, 1836 - sponges Class Calcarea Bowerbank, 1864 - calcareous sponges Order †Sphaerocoelida Vacelet, 1979 see Order Sphaerocoeliida Vacelet, 1979 Family Minchinellidae Dendy & Row, 1913 Genus †Muellerithalamia Reitner, 1987