Class Bivalvia Linnaeus, 1758 - bivalves Count: [*†*] 16o;110f; †6o;225f [31 Jan 2022] Subclass Autobranchia Grobben, 1894 Count: [*†*] 13o;98f; †6o;203f [31 Jan 2022] Superorder Heteroconchia Gray, 1854 Count: [*†*] 7o;75f; †3o;116f [31 Jan 2022] Clade Palaeoheterodonta Newell, 1965 Count: [*†*] 2o;7f; †27f [29 Jan 2022] Order Unionida Gray, 1854 Count: [*†*] 6f; †12f [29 Jan 2022] Superfamily †Trigonioidoidea Cox, 1952 Count: [†*] †6f [29 Jan 2022] Family †Trigonioididae Cox, 1952 Count: - Subfamily †Martinsonellinae Sha, 1993 Count: -