what invertebrate group are sponges belong to
Sponges are a group of invertebrates that includes glass sponges, demisponges, and calcareous sponges. There are about 10,000 species of sponges alive today. The earliest fossil evidence of sponges consists of various cells known to belong to spongesâspicules, pinacocytes, porocytes and archaeocytes.lthough there more than 30 phyla of invertebrates, and scientists are constantly reshuffling the way they classify them, in this article I'll keep it simple by focusing on just six basic groups of invertebrates.