Gryphaeidae

The Gryphaeidae, common name the foam oysters or honeycomb oysters, are a family of marine bivalve mollusks. This family of bivalves is very well represented in the fossil record, however the number of living species is very few.
All species have shells cemented to a substrate. Shells are considered brittle, inequivalve, with the left, lower valve convex and the right valve flat or slightly concave.

Subfamilies

Genera and species within this family are divided into three subfamilies, Exogyrinae, Gryphaeinae and Pycnodonteinae. Both Exogyrinae and Gryphaeinae are completely extinct. Only two genera Hyotissa and Neopycnodonte in the subfamily Pycnodonteinae have extant species.

Genera and species

Genera and species within the family Gryphaeidae include:
Family Gryphaeidae Vialov, 1936

Subfamily †Exogyrinae Vialov, 1936
*Genus †Aetostreon Bayle, 1878
*Genus †Amphidonte Fischer von Waldheim, 1829
*Genus †Costagyra Vialov, 1936
*Genus †Exogyra Say, 1820
*Genus †Fluctogyra Vialov, 1936
*Genus †Gryphaeostrea Conrad, 1865
*Genus †Gyrostrea Mirkamalov, 1963
*Genus †Ilymatogyra Stenzel, 1971
*Genus †Nanogyra Beurlen, 1958
*Genus †Nutogyra Vialov, 1936
*Genus †Planospirites Lamarck, 1801
*Genus †Vultogryphaea Vialov, 1936
Subfamily †Gryphaeinae Vialov, 1936
*Genus †Africogryphaea Freneix, 1963
*Genus †Deltoideum Rollier, 1917
*Genus †Gryphaea Lamarck, 1801
*Genus †Liostrea DouvillŽ, 1904
*Genus †Pernostrea Munier-Chalmas, 1864
*Genus †Praeexogyra Charles, 1952
Subfamily Pycnodonteinae Stenzel, 1959
*Genus †Gigantostrea
*Genus Hyotissa Stenzel, 1971
*Genus †Labrostrea Vialov, 1936
*Genus Neopycnodonte Stenzel, 1971
*Genus †Pycnodonte
*Genus †Texigryphaea Stenzel, 1959
Subfamily Incertae sedis
* Genus †Rhynchostreon Bayle, 1878