A sunshell is a type of shell that can be found on beaches. They are often called sun shells because they are often bright in color and shiny. Sunshells are made by many different types of animals, but the most common type is the gastropod. Gastropods are a type of mollusk, which also includes clams, oysters, and mussels. Sunshells vary in size, but the average size is about 2 inches long.