Invertebrate
From Conservapedia
An invertebrate (in contrast to a vertebrate), is an animal with no spine.[1]
Most living things are invertebrates, including arthropods, molluscs, and bacteria.
Sharks and rays are a special class under this description, since they do not have bony skeletons, and hence no spine. They do, however, have a similar structure to vertebrates. They are called notochords.
The phyla contained in Invertebrata are:
- Protozoa - Mostly simple, single-celled organisms
- Porifera - Sponges
- Coelentera - 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.[2]
