How to Classify Shells

Most shells found on beaches are from marine mollusks, a large phylum of invertebrate animals.

A seashell is a hard and protective outer layer created by a sea-dwelling animal. Seashell types fall into specific classes of mollusks, and the most common are gastropods, univalves, chitons, bivalves and scaphopods. Many books and websites offer photographs and additional information that can help you with classification. To properly identify your seashell, you must first examine its size, shape, markings and texture.

Instructions

1. Examine the seashell in question for binds or hinges that connect the top and bottom halves of the shell, sort of like a clam. If the shell has a join, it is a bilateral or bivalve shell.

2. Feel the seashell's texture. If it is smooth, long and curls into a tight shape, it is a gastropod or univalve shell.

3. Inspect the seashell's size and shape. If it is flattened and plated, and very primitive in appearance, it is a chiton shell. On the other hand, if it is tusk or tooth-like, the seashell is a scaphopod.

4. Visit shell identification Web sites and compare your shell to photographs online for further identification and classification.

5. Utilize online resources that teach visitors how to properly classify seashells. See "Lesson Planet" in Resources for access to lesson plans.

References

• Seashells by Millhill; Classifying Seashells; September 2010
• Yale-New Haven Teachers Institute; Shells; Nancy Wyskiel
• Coastal Care: Seashells

Resources

• Lesson Planet: Classifying Seashells Lesson Plans