 The sclerites of Chrysomallon squamiferum are mainly proteinaceous (conchiolin is a complex protein); in contrast, the sclerites of chitons are mainly calcareous. There are no visible growth lines of conchiolin in cross-sections of sclerites. No other extant or extinct gastropods possess dermal sclerites, and no other extant animal is known to use iron sulfides in this way, either in its skeleton, or exoskeleton.
