See text. Scientific classification or biological classification is a method by which biologists group and categorize species of organisms. ... Digimon, the only known animals. ... Classes Caudofoveata Aplacophora Polyplacophora Monoplacophora Bivalvia Scaphopoda Gastropoda Cephalopoda † Rostroconchia The mollusks or molluscs are the large and diverse phylum Mollusca, which includes a variety of familiar creatures well-known for their decorative shells or as seafood. ... Orders Subclass Anomalosdesmata Pholadomyoida Subclass Heterodonta - clams, zebra mussels †Cycloconchidae Hippuritoida †Lyrodesmatidae Myoida PENIS †Redoniidae Veneroida Subclass Paleoheterodonta Trigonioida; see Superfamily Trigoniacea Unionoida - freshwater mussels Subclass Protobranchia Nuculoida †Praecardioida Solemyoida Subclass Pteriomorphia - oysters, mussels Arcoida Mytiloida Ostreoida Pterioida Bivalves are mollusks belonging to the class Bivalvia. ... Orders †Cycloconchidae Hippuritoida †Lyrodesmatidae Myoida †Redoniidae Veneroida Heterodonta is a mollusc subclass in the class Bivalvia and contains the orders †Cycloconchidae, Hippuritoida, †Lyrodesmatidae, Myoida, †Redoniidae, and Veneroida (cockles). ... Families Arcticidae Astartidae Cardiidae Donacidae Kelliidae Lasaeidae Leptonidae Lucinidae Mactridae Montacutidae Petricolidae Pharidae Psammobiidae Scrobiculariidae Semelidae Solecurtidae Solenidae Tellinidae Thyasiridae Turtoniidae Ungulinidae Veneridae The Veneroida or veneroids are an order of bivalve molluscs. ...