Heterodonta
Heterodonta is a taxonomic subclass of saltwater clams, marine bivalve molluscs. This subclass includes the edible clams, the cockles and the Venus clams.
Description
These bivalves are distinguished by having the two halves of the shell equally sized and having a few cardinal teeth separated from a number of long lateral teeth. Their shells lack a nacreous layer, and the gills are lamellibranch in form. Most species have a siphon.Orders and families
In 2010, a new proposed classification system for the Bivalvia was published in by Bieler, Carter & Coan, revising the classification of the Bivalvia, including the subclass Heterodonta. The following tree is their info which has been updated with the latest information from the World Register of Marine Species:Subclass: Heterodonta
- Unclassified family: †Lipanellidae
- Infraclass: Archiheterodonta
- *Order: †Actinodontida
- **Superfamily: †Amnigenioidea
- ***Family: †Amnigeniidae
- ***Family: †Montanariidae
- ***Family: †Zadimerodiidae
- ** Superfamily: †Anodontopsoidea
- *** Family: †Actinodontidae
- *** Family: †Anodontopsidae
- *** Family: †Baidiostracidae
- *** Family: †Cycloconchidae
- *** Family: †Intihuarellidae
- *** Family: †Redoniidae
- ** Superfamily: †Nyassoidea
- *** Family: †Nyassidae
- ** Superfamily: †Oriocrassatelloidea
- *** Family: †Crassatellopsidae
- *** Family: †Oriocrassatellidae
- ** Superfamily: †Palaeomuteloidea
- *** Family: †Palaeomutelidae
- *Order: Carditida
- **Unclassified family: †Archaeocardiidae
- **Unclassified family: †Eodonidae
- **Superfamily: Carditoidea
- *** Family: †Cardiniidae
- ***Family: Carditidae
- ***Family: Condylocardiidae
- **Superfamily: Crassatelloidea
- ***Family: †Aenigmoconchidae
- ***Family: Astartidae
- ***Family: Crassatellidae
- ***Family: †Myophoricardiidae
- Infraclass: Euheterodonta
- *Unassigned Euheterodonta
- **Superfamily: †Babinkoidea
- **Superfamily: †Orthonotoidea
- *Superorder: Anomalodesmata
- **Superfamily: Clavagelloidea
- ***Family: Clavagellidae
- ***Family: Penicillidae
- **Superfamily: Cuspidarioidea
- ***Family: Cuspidariidae
- ***Family: Halonymphidae
- ***Family: Protocuspidariidae
- ***Family: Spheniopsidae
- **Superfamily: Myochamoidea
- ***Family: Cleidothaeridae
- ***Family: Myochamidae
- **Superfamily: Pandoroidea
- ***Family: Lyonsiidae
- ***Family: Pandoridae
- **Superfamily: Pholadomyoidea
- ***Family: †Arenigomyidae
- ***Family: †Margaritariidae
- ***Family: Parilimyidae
- ***Family: Pholadomyidae
- ***Family: †Ucumariidae
- **Superfamily: Poromyoidea
- ***Family: Cetoconchidae
- ***Family: Poromyidae
- **Superfamily: Thracioidea
- ***Family: †Burmesiidae
- ***Family: Clistoconchidae
- ***Family: Laternulidae
- ***Family: Periplomatidae
- ***Family: Thraciidae
- **Superfamily: Verticordioidea
- ***Family: Euciroidae
- ***Family: Lyonsiellidae
- ***Family: Verticordiidae
- * Superorder: Imparidentia
- ** Unassigned Imparidentia
- *** Unassigned Family: †Palaeocarditidae
- ***Superfamily: Cyamioidea
- ****Family: Cyamiidae
- ****Family: Galatheavalvidae
- ****Family: Sportellidae
- ***Superfamily: Gaimardioidea
- ****Family: Gaimardiidae
- ***Superfamily: †Grammysioidea
- ****Family: †Grammysiidae
- ****Family: †Sanguinolitidae
- ***Superfamily: †Kalenteroidea
- ****Family: †Kalenteridae
- ** Order: Adapedonta
- *** Superfamily: †Edmondioidea
- ****Family: †Edmondiidae
- ****Family: †Pachydomidae
- ***Superfamily: Hiatelloidea
- ****Family: Hiatellidae
- ***Superfamily: Solenoidea
- ****Family: Pharidae
- ****Family: Solenidae
- **Order: Cardiida
- ***Superfamily: Cardioidea
- ****Family: Cardiidae
- ****Family: †Pterocardiidae
- ***Superfamily: Tellinoidea
- ****Family: Donacidae
- ****Family: †Icanotiidae
- ****Family: Psammobiidae
- ****Family: †Quenstedtiidae
- ****Family: Semelidae
- ****Family: Solecurtidae
- ****Family: †Sowerbyidae
- ****Family: †Tancrediidae
- ****Family: Tellinidae
- ****Family: †Unicardiopsidae
- **Order: Galeommatida
- ***Superfamily: Galeommatoidea
- ****Family: Basterotiidae
- ****Family: Galeommatidae
- ****Family: Lasaeidae
- **Order: Gastrochaenida
- ***Superfamily: Gastrochaenoidea
- ****Family: Gastrochaenidae
- **Order: †Hippuritida
- ***Suborder: †Hippuritidina
- ****Superfamily: †Caprinoidea
- *****Family: †Antillocaprinidae
- *****Family: †Caprinidae
- *****Family: †Caprinuloideidae
- *****Family: †Ichthyosarcolitidae
- ****Superfamily: †Radiolitoidea
- *****Family: †Caprinulidae
- *****Family: †Caprotinidae
- *****Family: †Diceratidae
- *****Family: †Hippuritidae
- *****Family: †Monopleuridae
- *****Family: †Plagioptychidae
- *****Family: †Polyconitidae
- *****Family: †Radiolitidae
- *****Family: †Trechmannellidae
- ***Suborder: †Requieniidina
- ****Superfamily: †Requienioidea
- *****Family: †Epidiceratidae
- *****Family: †Requieniidae
- **Order: Lucinida
- ***Superfamily: Lucinoidea
- ****Family: Lucinidae
- ****Family: †Mactromyidae
- ****Family: †Paracyclidae
- ***Superfamily: Thyasiroidea
- ****Family: Thyasiridae
- **Order: †Megalodontida
- ***Superfamily: †Mecynodontoidea
- ****Family: †Beichuaniidae
- ****Family: †Congeriomorphidae
- ****Family: †Mecynodontidae
- ****Family: †Plethocardiidae
- ****Family: †Prosocoelidae
- ***Superfamily: †Megalodontoidea
- ****Family: †Ceratomyopsidae
- ****Family: †Dicerocardiidae
- ****Family: †Megalodontidae
- ****Family: †Pachyrismatidae
- ****Family: †Wallowaconchidae
- **Order: †Modiomorphida
- ***Superfamily: †Modiomorphoidea
- ****Family: †Cypricardiniidae
- ****Family: †Hippopodiumidae
- ****Family: †Modiomorphidae
- ****Family: †Palaeopharidae
- ****Family: †Tusayanidae
- **Order: Myida
- ***Superfamily: Dreissenoidea
- ****Family: Dreissenidae
- ***Superfamily: Myoidea
- ****Family: Corbulidae
- ****Family: Myidae
- ****Family: †Pleurodesmatidae
- ****Family: †Raetomyidae
- ***Superfamily: Pholadoidea
- ****Family: Pholadidae
- ****Family: Teredinidae
- ****Family: Xylophagaidae
- ***Superfamily: †Pleuromyoidea
- ****Family: †Ceratomyidae
- ****Family: †Pleuromyidae
- ****Family: †Vacunellidae
- **Order: Sphaeriida
- ***Superfamily: Sphaerioidea
- ****Family: †Neomiodontidae
- ****Family: Sphaeriidae
- **Order: Venerida
- ***Superfamily: †Anthracosioidea
- ****Family: †Anthracosiidae
- ****Family: †Ferganoconchida
- ****Family: †Shaanxiconchidae
- ***Superfamily: Arcticoidea
- ****Family: Arcticidae
- ****Family: †Pollicidae
- ****Family: Trapezidae
- ****Family: †Veniellidae
- ***Superfamily: Chamoidea
- ****Family: Chamidae
- ***Superfamily: Cyrenoidea
- ****Family: Cyrenidae
- ****Family: Cyrenoididae
- ****Family: Glauconomidae
- ***Superfamily: Glossoidea
- ****Family: Glossidae
- ****Family: Kelliellidae
- ****Family: †Lutetiidae
- ****Family: Vesicomyidae
- ***Superfamily: Hemidonacoidea
- ****Family: Hemidonacidae
- ***Superfamily: Mactroidea
- ****Family: Anatinellidae
- ****Family: Cardiliidae
- ****Family: Mactridae
- ****Family: Mesodesmatidae
- ***Superfamily: †Palaeanodontoidea
- ****Family: †Palaeanodontidae
- ***Superfamily: †Prilukielloidea
- ****Family: †Prilukiellidae
- ****Family: †Senderzoniellidae
- ***Superfamily: Ungulinoidea
- ****Family: Ungulinidae
- ***Superfamily: Veneroidea
- ****Family: †Isocyprinidae
- ****Family: Neoleptonidae
- ****Family: Veneridae
- Family †Lyrodesmatidae was classified by Bieler, Carter & Coan as uncertain Heterodonta but has since been classified as Palaeoheterodonta.
- Family †Redoniidae was classified by Bieler, Carter & Coan as uncertain Heterodonta but has since been classified more specifically as Anodontopsoidea.
- Family †Lipanellidae was classified by Bieler, Carter & Coan as uncertain Heteroconchia but has since been classified as uncertain Heterodonta.