Chitons are marine molluscs of varying size in the class Polyplacophora, formerly known as Amphineura. About 940 extant and 430 fossil species are recognized.
Lorica is a genus of chitons in the family Schizochitonidae.
Aviculopecten is an extinct genus of bivalve mollusc that lived from the Early Devonian to the Late Triassic in Asia, Australia, Europe, North America, and South America.
Chitonina is a suborder of polyplacophoran mollusc. The suborder includes both living and extinct species.
Lepidopleurina is a suborder of polyplacophoran molluscs. It includes both extinct and extant species.
Septemchiton is an extinct genus of polyplacophoran molluscs. Septemchiton became extinct during the Ordovician period.
Leptochitonidae is a family of polyplacophoran mollusc. While the subfamily Leptochitoninae has both extant and extinct species, all members of Helminthochitoninae are extinct.
Calceochiton is an extinct genus of polyplacophoran molluscs. Calceochiton became extinct during the Ordovician period.
Olingechiton is an extinct genus of polyplacophoran molluscs. Olingechiton became extinct at the end of the Cretaceous period.
Gotlandochiton is an extinct genus of polyplacophoran mollusc. Gotlandochiton became extinct during the Silurian period.
Ivoechiton is an extinct genus of polyplacophoran molluscs. Ivoechiton became extinct during the Cretaceous period.
Kindbladochiton is an extinct genus of polyplacophoran molluscs. Kindbladochiton became extinct during the Ordovician period.
Helminthochiton is an extinct genus of polyplacophoran mollusc. Helminthochiton became extinct during the Permian period.
Pterochiton is an extinct genus of polyplacophoran molluscs.
Pterygochiton is an extinct genus of polyplacophoran molluscs. Pterygochiton became extinct during the Carboniferous period.
Trachypleura is an extinct genus of polyplacophoran molluscs. Trachypleura became extinct during the Triassic period.
Heterochiton is an extinct genus of polyplacophoran mollusc. Heterochiton became extinct during the Jurassic period.
Oochiton is an extinct genus of polyplacophoran molluscs. Oochiton became extinct during the Miocene period.
Naticopsis is an extinct genus of small sea snails belonging to the family Neritopsidae.
