Phylum Mollusc consists of soft bodied animals, many with shells, that have been adapting for over 500 million years. The students have been observing the three classes and how their characteristics compare and contrast. Bivalves such as clams, oysters and mussels are invertebrate animals that consist of two hinged shells. During this dissection the children observe the foot for locomotion, the mantle that creates the shell, abductor muscles, gill system, and gastric glands. We also discovered the nacre layer that creates the iridescent component of the pearl!