Poriferans are commonly referred to as sponges. An early branching event in the history of animals separated the sponges from other metazoans. As one would expect based on their phylogenetic position, fossil sponges are among the oldest known animal fossils, dating from the Late Precambrian. Since then, sponges have been conspicuous members of many fossil communities; the number of described fossil genera exceeds 900. The approximately 5,000 living sponge species are classified in the phylum Porifera, which …
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showed last 75 words of 232 total
…the beating of flagella which line the surface of chambers connected by a series of canals. Sponge cells perform a variety of bodily functions and appear to be more independent of each other than are the cells of other animals. There is an exception to the general description of sponge feeding that you just read above. Read more in the Life History & Ecology section to learn about the weird and interesting carnivorous sponges.