Sponges (micro-structure)

The Coelenterata are an obsolete phylum which encompassed sponges and Cnidarians (and Ctenophora within Cnidaria).  The  phylum Porifera is now classified as the most basal of the eumatetazoan phyla being derived from the sister taxon to eumetazoans, single celled choanoflagellates.  This wall chart shows some organisation of sponge filtration systems (1, 2, 4, 5 & 9) as well as the structure of some spicules (7, 8, 11 & 13) that are the mineralised fraction of the sponge body and are bound together by the protein spongin.