Metazoa		Bivalvia
MOLLUSCA		BivalvE Cladogram

Page Back	Unit Back	Metazoa	Metazoa References	Metazoa Cladogram	Pieces	Taxon Index
Page Next	Unit Next	Unit Home	References	Cladogram	Glossary	Time

Bivalve Cladogram

MOLLUSCA 
BASAL MOLLUSCA
|--Diasoma
|  |--Rostroconchia  
|  `--BIVALVIA  
|     |--Protobranchia  
|     `--HETERODONTA  
`--CYRTOSOMA
   |--CEPHALOPODA
   `--GASTROPODA 
      |--Eogastropoda  
      `--APOGASTROPODA
         |--Caenogastropoda
         `--HETEROBRANCHIA
            |--Opisthobranchia
            `--PULMONATA

The molecular phylogeny has brought about a radical transformation in Bivalve systematics, with several venerable groups shown to be artificial. The cladogram by Adamkewicz et al. (1997) give the relationships between a number of taxa, including a rather unusal clade uniting the Anomalodesmata and several Protobranch taxa. This finding has not been repliacted in other work.

A slightly more recent cladogram is by Giribet & Carranza (1999):

The following cladogram - which shows mostly recent groups (I hope to add more fossil taxa at a later date) is based on Parker (1982) as modified by Giribet & Wheeler (2002), who use molecular evidence from gene sequence data to create a phylogenetic estimate for bivalve molluscs, and Campbell (2002), who uses paleontological as well as molecular evidence. Giribet and Wheeler's combined analysis supports the monophyly of bivalves, paraphyly of protobranchiate bivalves, and monophyly of Autolamellibranchiata, Pteriomorphia, Heteroconchia, Palaeoheterodonta, and Heterodonta s.l. (the latter including the monophyletic taxon Anomalodesmata). The monophyly of Palaeoheterodonta is among the most stable of the results, grouping the extant trigoniids with the freshwater unionids, and the sister-group relationship of the heterodont families Astartidae and Carditidae, which together constitute the sister taxon to the remaining heterodont bivalves. However, the heterodont orders Myoida and Veneroida are not monophyletic.

The traditional subclasses (even when paraphyletic) are shown in bold.

<==o BIVALVIA [Pelycopoda, Lamellibranchia]
   |?--Tuarangioida
   `--+--Fordilla
      `--+--Pojetaia
         o PROTOBRANCHIA [Paleotoxodonta, Cryptodonta] 
         |--o NUCULOIDA
         |  |--o NUCULACEA
         |  |  |-- Nuculidae 
         |  |  `-- Pristiglomidae
         |  `--o NUCULANACEA
         |     |-- Nuculanidae [+Sareptidae, Ledidae, Zealedidae, Adranidae,Porolepididae] 
         |     |-- Tindariidae
         |     |-- Malletiidae 
         |     |-- Phaseolidae [Radiidentidae, Siliculidae]
         |     `-- Lametilidae
         |--o SOLEMYOIDA
         |  `--o SOLEMYACEA*
         |     |-- Solemyidae [+Acharacidae, Solenomyidae, Solemyacidae, Solenomyacidae]
         |     `-- Nucinellidae [+Huxleyidae, Manzanellidae]
         |--o PRAECARDOIDA
         `--o Plesion or Subclass AUTOBRANCHIA / AUTOLAMELLIBRANCHIATA
            `--+-- MODIOMORPHOIDA (Autolamellibranchia stem group)
               |--o PTERIOMORPHIA
               |  |--o ISOFILIBRANCHIA
               |  |  `--o MYTILOIDA
               |  |     `--o MYTILACEA 
               |  |        `-- Mytilidae 
               |  |--o PRIONODONTA [Taxodonta]
               |  |   `--o ARCOIDA*
               |  |      |--o ARCACEA
               |  |      |  |-- Arcidae [+Anadaridae] 
               |  |      |  |-- Noetiidae
               |  |      |  |-- Parallelodontidae [+Macrodontidae]
               |  |      |  `-- Cucullaeidae
               |  |      `--o LIMOPSACEA
               |  |         |-- Limopsidae
               |  |         |-- Glycymerididae [+Glycymeridae, Pectunculidae] 
               |  |         `-- Philobryidae
               |  `--o EUPTERIDOMORPHA [Anisomyaria, in partim]
               |      |--o PTERIINA
               |      |  |--o PTERIACEA* 
               |      |  |  |-- Pteriidae [+Aviculidae] (siipisimpukat)
               |      |  |  |-- Malleidae [Vulsellidae, Eligmidae, Stefaniniellidae]
               |      |  |  |-- Isognomonidae [+Melinidae, Pernidae, Isognomontidae]
               |      |  |  `-- Pulvinitidae
               |      |  `--o PINNINA
               |      |     `--o PINNACEA 
               |      |        `-- Pinnidae 
               |      |--o LIMOIDA
               |      |  `--o LIMACEA 
               |      |     `-- Limidae* [Limaridae, Radulidae] 
               |      `--o OSTREOIDA 
               |         |--o OSTREINA
               |         |  |--o OSTREACEA 
               |         |  |  |-- Ostreidae 
               |         |  |  `-- Gryphaeidae
               |         |  |--o DIMYACEA
               |         |  |  `-- Dimyidae*
               |         |  `--o PLICATULACEA
               |         |     `-- Plicatulidae*
               |         `--o PECTININA
               |            |--o PECTINACEA
               |            |  |-- Pectinidae [+Entoliidae]
               |            |  |-- Spondylidae
               |            |  |-- Syncyclonemidae
               |            |  `-- Propeamussiidae [+Amusiidae]
               |            `--o ANOMIACEA
               |               |-- Anomiidae
               |               `-- Placunidae
               `--+--o PALAEOHETERODONTA [Schizodonta]
                  |   |--o TRIGONIOIDA
                  |   |  `--o TRIGONIACEA*
                  |   |     `-- Trigoniidae*
                  |   `--o UNIONOIDA
                  |      |--o UNIONACEA
                  |      |  |-- Unionidae [Lampsilidae] 
                  |      |  |-- Amblemidae
                  |      |  |-- Margaritiferidae [Margaritanidae] 
                  |      |  `-- Hyriidae [+Hyridellidae, Hyridinidae, Diplodontidae, Propehyridellidae]
                  |      `--o MUTELACEA
                  |         |-- Mutelidae [+Mutellidae]
                  |         |-- Mycetopodidae
                  |         `-- Etheriidae [Aetheriidae, Pseudomulleridae, Mulleridae]
                  `--o HETERODONTA 
                     `--+--o unnamed clade [note] 
                        |  |--o CARDITACEA 
                        |  |  |-- Carditidae
                        |  |  `-- Condylocardiidae
                        |  `--o CRASSATELLACEA [+Astartacea]
                        |     |-- Crassatellidae
                        |     |-- Astartidae [+Crassinidae] 
                        |     `-- Cardiniidae
                        `--o unnamed clade
                           |--o HIPPURITOIDA
                           |--o CHAMACEA
                           |  `-- Chamidae
                           `--+--o VENEROIDA
                              |  `--o LUCINACEA (Veneroid stem group (Campbell, 2002)
                              |     |-- Lucinidae
                              |     |-- Fimbriidae [+Corbidae]
                              |     |-- Mactromyidae [+Mactromyacidae]
                              |     |-- Thyasiridae [+Cryptodontidae]
                              |     |-- Ungulinidae [+Diplodontidae]
                              |     |-- Cyrenoididae [+Cyrenellidae]
                              |     `--+--o LEPTONACEA
                              |        |  |-- Leptonidae [+Myllitidae]
                              |        |  |-- Lasaeidae [+Erycinidae, Kelliidae, Montacutidae, Borniolidae, Mysellidae]
                              |        |  |-- Galeommatidae
                              |        |  `-- Chlamydoconchidae
                              |        |--o CYAMIACEA
                              |        |  |-- Cyamiidae [+Perrierinidae]
                              |        |  |-- Gaimardiidae
                              |        |  |-- Sportellidae [+Basterotiidae]
                              |        |  |-- Neoleptonidae
                              |        |  `-- Galatheavalvidae
                              |        |--o CARDIACEA
                              |        |  |-- Cardiidae
                              |        |  |-- Lymnocardiidae [+Adacnidae]
                              |        |  `-- Hemidonacidae
                              |        |--o TRIDACNACEA
                              |        |  `-- Tridacnidae
                              |        |--o MACTRACEA
                              |        |  |-- Mactridae [+Tanysiphonidae] 
                              |        |  |-- Mesodesmatidae [+Amphidesmatidae, Paphiidae]
                              |        |  |-- Cardiliidae
                              |        |  `-- Anatinellidae
                              |        |--o SOLENACEA
                              |        |  |-- Solenidae 
                              |        |  `-- Cultellidae [+Pharellidae]
                              |        |--o TELLINACEA
                              |        |  |-- Tellinidae 
                              |        |  |-- Psammobiidae [+Garidae, Asaphidae, Sanguinolariidae]
                              |        |  |-- Solecurtidae [+Pharinidae]
                              |        |  |-- Semelidae
                              |        |  |-- Scrobiculariidae
                              |        |  `-- Donacidae
                              |        |--o ARCTICACEA [+Cypricardiacea, Trapezacea]
                              |        |  |-- Arcticidae
                              |        |  |-- Trapeziidae
                              |        |  `-- Bernardinidae
                              |        |--o GLOSSACEA [+Isocardiacea]
                              |        |  |-- Glossidae [+Isocardiidae]
                              |        |  |-- Vesicomyidae [+Vesicomyacidae]
                              |        |  `-- Kelliellidae [+Kellyellidae]
                              |        |--o DREISSENACEA
                              |        |  `-- Dreissenidae (vaeltajasimpukat)
                              |        |--o CORBICULACEA [+Cyrenacea, Sphaeriacea]
                              |        |  |-- Corbiculidae [+Cyrenidae, 
                              |        |  `-- Pisidiidae [+Cycladidae, Sphaeridae, Euperidae]
                              |        |--o VENERACEA
                              |        |  |-- Veneridae (venussimpukat)
                              |        |  |-- Petricolidae
                              |        |  |-- Glauconomidae [+Glaucomyidae, Glauconomyidae, Glauconomeidae]
                              |        |  |-- Cooperellidae
                              |        |  `-- Turtoniidae
                              |        `--o "MYOIDA" (polyphyletic - derived from Veneroida (Campbell, 2002)
                              |           |--o MYACEA
                              |           |  |-- Myidae [+Myacidae] 
                              |           |  |-- Corbulidae [+Aloididae]
                              |           |  |-- Erodonidae
                              |           |  `-- Spheniopsidae
                              |           |--o GASTROCHAENACEA
                              |           |  `-- Gastrochaenidae*
                              |           |--o HIATELLACEA
                              |           |  `-- Hiatellidae* [+Saxicavidae, Glycimeridae]
                              |           `--o PHOLADACEA
                              |              |-- Pholadidae [Pholadidae]
                              |              `-- Teredinidae
                              `--o ANOMALODESMATA [+Septibranchia] (Veneroid sister group (Campbell, 2002)
                                 |--o PHOLADOMYACEA
                                 |  `-- Pholadomyidae*
                                 |--o PANDORACEA
                                 |  |-- Thraciidae
                                 |  |-- Laternulidae [+Anatinidae]
                                 |  |-- Periplomatidae [+Periplomidae]
                                 |  |-- Lyonsiidae
                                 |  |-- Pandoridae
                                 |  |-- Myochamidae
                                 |  `-- Cleidothaeridae [+Chamostreidae]
                                 |--o CLAVAGELLACEA
                                 |  `-- Clavagellidae* [+Aspergiliidae], Penicillidae, Humphreyidae]
                                 `--o POROMYACEA [Septibranchia]
                                    |-- Poromyidae 
                                    |-- Cuspidariidae
                                    `-- Verticordiidae

Notes

Not veneroids (Campbell, 2002); sister taxon to the remaining heterodonts (Giribet & Wheeler, 2002)
back