Phylum Porifera Grant, 1836 - sponges Class Demospongea Sollas, 1875 see Class Demospongiae Sollas, 1885 Subclass Clavaxinellida Lévi, 1956 Order Protomonaxonida Finks & Rigby, 2004 Family †Piraniidae de Laubenfels, 1955 1 Genus †Moleculospina Rigby, 1986 2 Genus †Pirania Walcott, 1920