Belongs within: Bivalvia.Contains: Hippuritacea, Neomiodontidae, Gastrochaenidae, Montacutidae, Lasaeidae, Sportellidae, Thyasira, Lucinidae, Solenoidea, Tellinoidea, Neoheterodontei, Cardiidae, Panopea. The Heterodonta are one of the major living clades of bivalves, with their earliest representatives appearing in the Ordovician. In the past, the living members of the clade were divided between the orders Veneroida and Myoida (the latter including… Continue reading Heterodonta


Belongs within: Heterodonta.Contains: Psammobia, Gari, Donax, Iphigenia, Galatea, Solecurtidae, Macoma, Semele, Tellina, Arcopagia, Angulus, Strigilla. The Tellinoidea are a group of infaunal bivalves that first appeared in the Upper Triassic. With their elongate, mobile siphons, tellinoids tend to burrow relatively deep within the sediment, using the siphons to pick up food particles from the sediment… Continue reading Tellinoidea


Belongs within: Tellinoidea. Tellina is a genus of burrowing heterodont bivalves that first appeared in the Lower Cretaceous. The shell is somewhat elongate with an external ligament and more or less unequal valves. In life, they lie obliquely in the substrate on their left valve with the more inflated and convex right valve upwards (Beesley… Continue reading Tellina


Belongs within: Tellinoidea. Donax is a cosmopolitan genus of infaunal bivalves with heavy, triangular shells and a large foot adapted for rapid burrowing (Beesley et al. 1998). <==Donax Linnaeus 1758L58 |–D. aperittusM01 |–D. assimilisC64 |–D. brazieri Smith 1891H09 |–D. californicusC64 |–D. carinata Hanley 1843H43 |–D. clathratus Desh. 1859M01 |–D. columbella Lamarck 1818S-S90 |–D. conradiC64 |–D.… Continue reading Donax


Belongs within: Cardiinae. Cardium is a genus of cockles with radial ribs strongly expressed internally and spines modified into hollow keels (Schneider 2002). <==Cardium Linnaeus 1758L58 |–C. aculeatumH04 |–C. bechei Reeve 1847H09 |–C. biangulatumC64 |–C. biradiatum Bruguière 1789H09 |–C. blandum Gould 1850 [=C. (Cerastoderma) blandum]S02 |–C. californiense Deshayes 1839 [=C. (Cerastoderma) californiense]S02 |–C. cardissa Linnaeus… Continue reading Cardium


Belongs within: Cardiidae.Contains: Cardium. The Cardiinae, cockles, are a clade of burrowing bivalves. The scope of the Cardiinae was restricted by Schneider (2002) who removed taxa such as the Orthocardiinae whose inclusion made Cardiinae paraphyletic with regards to other subfamilies of the family Cardiidae. The same study identified a number of subclades within the Cardiinae… Continue reading Cardiinae


Belongs within: Neoheterodontei. Chama is a genus of superficially oyster-like bivalves found primarily in tropical regions. They are normally cemented to their substrate by the left valve, though individuals may sometimes be found cemented by the right valve (Darragh & Kendrick 2008). Such variation raises questions about the genus’ distinction from the closely related Pseudochama… Continue reading Chama


Belongs within: Neoheterodontei.Contains: Teredininae, Martesiinae, Pholas. The Pholadoidea are a clade of two families of bivalves, Pholadidae and Teredinidae, which are adapted for boring into hard substrates (rock or wood in the case of Pholadidae, wood for Teredinidae) using their shells to grind out a burrow. Teredinids, commonly known as shipworms, are particularly derived, with… Continue reading Pholadoidea


Belongs within: Heterodonta. The Solenoidea, razor shells, are thin-shelled, infaunal bivalves that live in more or less permanent tubes oriented vertically or obliquely in the sediment (Beesley et al. 1998). Characters (from Beesley et al. 1998): Shell thin, fragile, narrowly elongate, rectangular, cylindrical or laterally compressed, gaping widely at each end. Shell comprising two aragonitic… Continue reading Solenoidea


Belongs within: Neoheterodontei.Contains: Mya, Corbula, Neaera. The Myoidea, soft-shell clams, are a group of infaunal bivalves first recorded from the Upper Jurassic. Within the group, the Myidae have the shells elongate and chalky with a wide posterior gape. The Pacific Spheniopsidae have more or less equivalve shells like Myidae but stronger sculpture of commarginate ridges… Continue reading Myoidea