The Chitons (Polyplacophora) - class

(Haeggochitonidae)
- family

(Ivoechitonidae)
- family

(Olingechitonidae)
- family

(Scanochitonidae)
- family -extinct-
(Paleoloricata) - order
(Chelodida) - suborder

(Chelodidae)
- family
(Septemchitonida) - order

(Gotlandochitonidae)
- family

(Helminthochitonidae)
- family

(Septemchitonidae)
- family
(Loricata) - subclass
(Chitonida) - order
(Acanthochitonina) - suborder
(Cryptoplacoidea) - superfamily

(Acanthochitonidae)
- family

(Choriplacidae)
- family

(Cryptoplacidae)
- family

(Hemiarthridae)
- family
(Mopalioidea) - superfamily

(Mopaliidae)
- family

(Schizoplacidae)
- family

(Tonicellidae)
- family
(Chitonina) - suborder
(Chitonoidea) - superfamily

(Callistoplacidae)
- family

(Callochitonidae)
- family

(Chaetopleuridae)
- family

(Chitonidae)
- family

(Ischnochitonidae)
- family

(Loricidae)
- family

(Ochmazochitonidae)
- family
(Schizochitonoidea) - superfamily

(Schizochitonidae)
- family
(Lepidopleurida) - order
(Cymatochitonina) - suborder

(Acutichitonidae)
- family

(Cymatochitonidae)
- family

(Gryphochitonidae)
- family

(Lekiskochitonidae)
- family

(Permochitonidae)
- family
(Lepidopleurina) - suborder

(Abyssochitonidae)
- family

(Camptochitonidae)
- family

(Glyptochitonidae)
- family

(Hanleyidae)
- family

(Leptochitonidae)
- family

(Mesochitonidae)
- family

(Nierstraszellidae)
- family

(Protochitonidae)
- family