Mollusca, Schizopea sp.

• Schizopea is a small marine snail found in Cambrian and Ordovician sediments in the eastern half of the United States, and also in South Korea. The specimen pictured is from the state of Missouri.

• Scientists have spent much effort trying to determine to what group it belongs, and have concluded that it is one of the first gastropods to appear in the fossil record.

• Schizopea may have fed by scraping algae from rocks, or by trapping microorganisms in the cilia.

• Today, there are more than 65,000 species of gastropods, making them probably the most diverse type of marine invertebrate.