Cassids [Cassidae]

Description

Cassidae, known as helmet shells or cassids, are a family of large sea snails. These marine gastropod mollusks have thick, heavy shells with a distinctive helmet-like shape, hence their common name. The aperture of the shell is often small relative to the overall size of the shell. Cassids are carnivorous, feeding mainly on echinoderms such as sea urchins. They are found in sandy or muddy substrates in tropical and temperate seas around the world.