''Platyceramus'' was a genus of

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 ...

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

mollusc 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 ...

s belonging to the extinct

inoceramid The Inoceramidae are an extinct family (biology), family of bivalves ("clams") in the Class Mollusca. Fossils of inoceramids are found in marine sediments of Permian to latest Cretaceous in age. Inoceramids tended to live in upper bathyal and ner ...

lineage. It is sometimes classified as a

subgenus In biology, a subgenus ( subgenera) is a taxonomic rank directly below genus. In the International Code of Zoological Nomenclature, a subgeneric name can be used independently or included in a species name, in parentheses, placed between the ge ...

of ''

Inoceramus ''Inoceramus'' (Greek: translation "fibrous shell" for the fibrous structure of the mineral crystals in the shell) is an extinct genus of fossil marine pteriomorphian bivalves that superficially resembled the related winged pearly oysters of th ...

''.

Size

The largest and best known species is ''P. platinus''. Individuals of this species typically reached or more in axial length, but some exceptional specimens long have been found,Journal of Paleontology , Jan., 2007, Vol. 81, No. 1 (Jan., 2007), pp. 64-81 making it the largest known bivalve. Its huge but very thin shell often provided shelter for schools of small fish, some of which became trapped and fossilised themselves. The outer shell often provided

habitat In ecology, habitat refers to the array of resources, biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species' habitat can be seen as the physical manifestation of its ...

for its own juveniles, also for

oysters Oyster is the common name for a number of different families of Seawater, salt-water bivalve molluscs that live in Marine (ocean), marine or Brackish water, brackish habitats. In some species, the valves are highly Calcification, calcified, a ...

such as the

epizoic An epibiont (from the Ancient Greek meaning "living on top of") is an organism that lives on the surface of another living organism, called the basibiont ("living underneath"). The interaction between the two organisms is called epibiosis. An ep ...

oyster '' Pseudoperna congesta'', and

barnacle Barnacles are arthropods of the subclass (taxonomy), subclass Cirripedia in the subphylum Crustacean, Crustacea. They are related to crabs and lobsters, with similar Nauplius (larva), nauplius larvae. Barnacles are exclusively marine invertebra ...

s. Shells containing pearls have also been discovered.

References

External links

Paleoecology of giant Inoceramidae (Platyceramus) on a Santonian (Cretaceous) seafloor in Colorado

Inoceramidae Prehistoric bivalve genera Cretaceous bivalves Mesozoic molluscs of Europe Prehistoric bivalves of North America Fossil taxa described in 1932 {{paleo-bivalve-stub