Finally, Ecphora gardnerae is the symbol of the Paleontological Research Institution. Snails are related to slugs, sea slugs, sea hares, limpets, and abalones. Together, these animals are called gastropods. Most gastropods have a spiral shell into which the animal can retract. Gastropods also have a head equipped with antennae, eyes, and mouth, and a large foot.
Gastropods are the most common members of a group of animals called mollusks.
Other mollusks include bivalves, such as clams and oysters, and octopuses and squids. Just as insects are the most familiar invertebrates on land, so are mollusks the most familiar invertebrates in the water. Most of its fossils are found along the coast, and these are mostly marine animals from the Cenozoic Era, or Age of Mammals. Here the Calvert Cliffs harbor fossils of hundreds of different kinds of animals that lived twelve to twenty-five million years ago, during the Miocene Epoch. The Calvert Cliffs preserve the most complete record of Miocene animals on the East Coast.