Class Gastropoda (Snails and slugs):
* Snails: These are the most common shelled mollusks. Their shells are typically spiral-shaped and can come in a variety of colors and patterns.
* Slugs: These are snails that have lost their shells over time. However, some slugs still have a small, internal shell.
Class Bivalvia (Clams, mussels, oysters):
* Clams: These mollusks have two shells that hinge together. They are often found buried in sand or mud.
* Mussels: These mollusks are similar to clams, but their shells are usually more elongated.
* Oysters: These mollusks are also bivalves, but their shells are irregular and often bumpy.
Class Cephalopoda (Squid, octopus, cuttlefish):
* Nautilus: This cephalopod has an external, spiral-shaped shell that is divided into chambers.
* Cuttlefish: These cephalopods have a flattened, internal shell called a cuttlebone.
Other Shelled Animals:
* Turtles: While not mollusks, turtles are reptiles that have a hard, bony shell that protects their body.
* Tortoises: These are land-dwelling turtles that have a high, dome-shaped shell.
Note: Some animals may have a shell-like structure but are not classified as mollusks, such as:
* Crustaceans (crabs, lobsters, shrimp): Their outer covering is called an exoskeleton, which is made of chitin.
* Brachiopods: These marine animals have a hinged shell, but they are not closely related to bivalves.
It's important to remember that there are many other fascinating shelled creatures out there!