Cardiinae

Chesacardium sp., from Calvert Marine Museum.

Belongs within: Cardiidae.
Contains: Cardium.

The Cardiinae, cockles, are a clade of burrowing bivalves. The scope of the Cardiinae was recently 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 sensu lato, including an association of Dinocardium, Vepricardium, Bucardium and Cardium united by having ribs strongly expressed internally, ridges on the lunule flap, a concave nymph, a dorsal nymph flare and a right ventral lateral tooth that continues into the umbo. The genus Acanthocardia is characterised by nodes or spines on the ribs.

See also: The calcareous heart.

Synapomorphies (from Schneider 2002): Shell shape schediform; notches present on posterodorsal portion of spines; non-denticulate composite prismatic prisms present in prismatic outer shell layer.

<==Cardiinae
    |  i. s.: Cerastoderma S02
    |           |--C. chancellorensis Oleksyshyn 1959 S02
    |           `--C. edule (Linnaeus 1758) TW07
    |--Schedocardia hatchetigbeense (Aldrich 1886) S02
    `--+--Acanthocardia S02
       |    |--A. (Acanthocardia) aculeata (Linnaeus 1758) S02
       |    |--A. echinata (Linnaeus 1758) GW02, L58 [=Cardium echinatum G84]
       |    `--A. (Rudicardium) tuberculata (Linnaeus 1758) S02
       |--+--Dinocardium robustum (Lightfoot 1786) [=Cardium (Cerastoderma) robustum] S02
       |  `--+--Vepricardium multispinosum (Sowerby 1834) S02
       |     `--+--Bucardium ringens (Bruguiere 1789) S02
       |        `--Cardium S02
       `--+--Planicardium Olsson 1967 S02
          |    |--*P. virginianum (Conrad 1839) (see below for synonymy) S02
          |    `--P. taeniopleura (Dall 1900) (see below for synonymy) S02
          `--Chesacardium Ward 1992 S02
               |--C. acutilaqueatum (Conrad 1839) (see below for synonymy) S02
               `--C. laqueatum Conrad 1830 [=Cardium (Cerastoderma) laqueatum] S02
                    |--C. l. laqueatum S02
                    `--C. l. blountense (Mansfield 1932) [=Cardium (Cerastoderma) laqueatum blountense] S02

Chesacardium acutilaqueatum (Conrad 1839) [=Cardium (Cerastoderma) acutilaqueatum, Clinocardium (Planicardium) acutilaqueatum] S02

Planicardium taeniopleura (Dall 1900) [=Cardium (Cerastoderma) taeniopleura, Clinocardium (Planicardium) taeniopleura] S02

*Planicardium virginianum (Conrad 1839) [=Cardium (Cerastoderma) virginianum, Clinocardium (Planicardium) virginianum] S02

*Type species of generic name indicated

REFERENCES

[GW02] Giribet, G., & W. Wheeler. 2002. On bivalve phylogeny: a high-level analysis of the Bivalvia (Mollusca) based on combined morphology and DNA sequence data. Invertebrate Biology 121 (4): 271–324.

[G84] Gosling, E. M. 1984. The systematic status of Mytilus galloprovincialis in western Europe: a review. Malacologia 25 (2): 551–568.

[L58] Linnaeus, C. 1758. Systema Naturae per Regna Tria Naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Tomus I. Editio decima, reformata. Laurentii Salvii: Holmiae.

[S02] Schneider, J. A. 2002. Phylogeny of cardiid bivalves (cockles and giant clams): revision of the Cardiinae and the importance of fossils in explaining disjunct biogeographical distributions. Zoological Journal of the Linnean Society 136: 321–369.

[TW07] Taylor, J. D., S. T. Williams, E. A. Glover & P. Dyal. 2007. A molecular phylogeny of heterodont bivalves (Mollusca: Bivalvia: Heterodonta): new analyses of 18S and 28S rRNA genes. Zoologica Scripta 36 (6): 587–606.

Last updated: 22 December 2021.