The Inoceramidae are an extinct

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

bivalves Bivalvia () or bivalves, in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of aquatic molluscs (marine and freshwater) that have laterally compressed soft bodies enclosed by a calcified exoskeleton consis ...

("clams") in the Class

Mollusca Mollusca is a phylum of protostome, protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant taxon, extant species of molluscs are recognized, making it the second-largest animal phylum ...

. Fossils of inoceramids are found in marine sediments of

Permian The Permian ( ) is a geologic period and System (stratigraphy), stratigraphic system which spans 47 million years, from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.902 Mya. It is the s ...

to latest

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...

in age. Inoceramids tended to live in upper bathyal and neritic environments. Many species of inoceramid are found all over the world, demonstrating the wide distribution of their preferred ecosystems, and possibly long-lived planktotrophic larvae.Lower Turonian Euramerican Inoceramidae: A morphologic, taxonomic, and biostratigraphic overview
A report from the first Workshop on Early Turonian Inoceramids (Oct. 5-8, 1992) in Hamburg, Germany; organized by Heinz Hilbrecht and Peter J. Harries Despite their wide distribution, the pace of evolution of inoceramids was great, with species ranges commonly averaging 0.2-0.5 Ma.

Size

Various species of inoceramids have achieved shell sizes ranging from small to large. Members of the '' Inoceramus'' and ''

Cladoceramus ''Cladoceramus'' is an extinct genus of fossil Marine (ocean), marine pteriomorphian bivalves that superficially resembled the related winged pearly oysters of the Extant taxon, extant genus ''Pteria (bivalve), Pteria''. They lived in the Santoni ...

'' genera have shells of more than in length. In 1952, a huge specimen of ''Inoceramus steenstrupi'' long, was found in Qilakitsoq, the Nuussuaq Peninsula,

Greenland Greenland is an autonomous territory in the Danish Realm, Kingdom of Denmark. It is by far the largest geographically of three constituent parts of the kingdom; the other two are metropolitan Denmark and the Faroe Islands. Citizens of Greenlan ...

. This fossil is 83 Ma old, the Upper

Santonian The Santonian is an age in the geologic timescale or a chronostratigraphic stage. It is a subdivision of the Late Cretaceous Epoch or Upper Cretaceous Series. It spans the time between 86.3 ± 0.7 mya ( million years ago) and 83.6 ± 0.7 m ...

or Lower

Campanian The Campanian is the fifth of six ages of the Late Cretaceous epoch on the geologic timescale of the International Commission on Stratigraphy (ICS). In chronostratigraphy, it is the fifth of six stages in the Upper Cretaceous Series. Campa ...

stage. Specimens referred to '' Antarcticeramus'' are also gigantic, some around 1.8 m and shell thicknesses of 3 cm.

Taxonomy

Inoceramidae Giebel, 1852 *Genus ''

Actinoceramus ''Actinoceramus'' is an extinct genus of fossil saltwater clams, marine pteriomorphian bivalve molluscs. These bivalves were facultatively mobile infaunal suspension feeders. ''Actinoceramus sulcatus'' marks the oldest appearance of well-dev ...

'' Meek, 1864 (Synonym = ''Birostrina'' De Luc & Sowerby, 1821) *Genus '' Anopaea'' Eichwald, 1861 *Genus '' Antarcticeramus'' Crame & Luther, 1997 *Genus '' Arctomytiloides'' Polubotko, 1992 *Genus '' Cataceramus'' Cox, 1969 *Genus ''

'' Seitz, 1961 *Genus '' Cremnoceramus'' Heinz, 1932 *Genus '' Endocostea'' Whitfield, 1877 *Genus '' Inoceramus'' Sowerby, 1814 **Subgenus ''Inoceramus (Cordiceramus)'' (Heinz, 1932) **Subgenus ''Inoceramus (Inoceramus)'' Sowerby, 1814 **Subgenus ''Inoceramus (Sphenoceramus)'' (Böhm, 1915) *Genus '' Magadiceramus'' Heinz, 1932 *Genus '' Mytiloides'' Brongniart, 1822 *Genus '' Neocomiceramus'' Pokhialainen, 1972 *Genus '' Neoinoceramus'' Ihering, 1902 *Genus '' Parainoceramus'' Voronetz, 1936 *Genus ''

Platyceramus ''Platyceramus'' was a genus of Cretaceous bivalve molluscs belonging to the extinct inoceramid lineage. It is sometimes classified as a subgenus of ''Inoceramus''. Size The largest and best known species is ''P. platinus''. Individuals of this ...

'' Heinz, 1932 *Genus '' Pseudomytiloides'' Koschelkina, 1963 *Genus '' Retroceramus'' Koschelkina, 1958 *Genus '' Spyridoceramus'' Cox, 1969 *Genus '' Tethyoceramus'' Sornay, 1980 *Genus '' Trochoceramus'' Heinz, 1932 *Genus '' Volviceramus'' Stoliczka, 1871

Size

Taxonomy

Footnotes

Further reading