GASTROPODS have coiled shells and are commonly known as snails. Today they live on land, in fresh water, and in seawater. Gastropods crawl about on a large, sticky foot (reconstructed in figure 2b). Some gastropods filter food from the water, some graze on plants, and some are carnivores that eat other animals. It is usually not possible to determine which of these feeding methods were used by Silurian gastropods.
At least 17 species of gastropods lived as dwellers in the Silurian reefs of Wisconsin. Three of these species, shown above, have been placed in the Silurian reef diorama. One of these species is sometimes found on crinoids (figure 1a) and may have fed on the crinoid's waste products.