Chaetoderma are in the Mollusca family, but are unique due to their lack of shell. Instead of using a shell for protection, they have a mantle, which secretes spicules made of calcium carbonate. This organism posses an odontophore, which is used to support the radula in the mouth. A dorsal gonad is present and opens into the peracardium. To excrete the waste, they use a pair of protonephridia. The most distinct features of this the Chaetodermais the presence of ventral suture, which is an indicator that these animals may have had an operculum.
Chaetoderma is a speciose genus of aplacophoran mollusc.[1] It has forty described species at present.