Porifera by Stephen Shachtman
Copper 8x12x36" one-of-a-kind
Porifera, or sponges, are the simplest and oldest of the multi-celled animals, with fossils dating back to Precambrian times. They are aquatic and sessile, living permanently attached to submerged objects. More than 5,000 species are known, most of which occur in shallow coastal waters and in the deep sea.