The phyla contained in Invertebrata are:
- Protozoa - Mostly simple, single-celled organisms
- Porifera - Sponges
- Coelenterata - Hydra, jellyfish, anemones and corals
- Echinoderma - Starfish, sea urchins and sea cucumbers
- Annelida - Worms
- Brachiopoda - Bivalves, such as mussels and clams
- Polyzoa - Single celled critters that usually form colonies
- Mullusca - Whelks, ammonites, cuttlefish, squids, snails, etc.
- Arthropoda - Crustaceans, insects, arachnids, trilobites, etc.