Minerals have been found in the radular teeth of molluscs from the classes Caudofoveata, Polyplacophora, Monoplacophora, and Gastropoda (Patellogastropoda: Acmaeidae, Patellidae). Here we report the discovery of amorphous iron oxide and hydroxyapatite in the highly modified radular apparatus of Falcidens sp. (Caudofoveata). The mineralization process in Falcidens sp. is unique: the components of the radular apparatus, unlike those of other molluscs, are not renewed during the animal's lifetime. We propose that the presence of mineralized teeth among the molluscs is not necessarily connected to their manner of obtaining food and suggest that the molluscan common ancestor had mineralized teeth.