Stratum.black
Inoceramus — Inoceramus
Inoceramus — Wilson44691, Wikimedia Commons, Public domain (US)

Bivalve

Inoceramus

Inoceramid clam

Inoceramus and its relatives are the giant Cretaceous clams of the Western Interior Seaway, up to a metre across in the Niobrara Chalk, with a prismatic calcite shell that weathers into 'inoceramite' fragments. Whole valves with attached oysters and fish nestling inside are collected; the prismatic shell is also cut and polished. They are useful index fossils across the Cretaceous.

PhylumMollusca
ClassBivalvia
OrderPteriida
FamilyInoceramidae
GroupBivalve
Rank (PBDB)genus· Paleobiology Database
AuthorSowerby 1814· Paleobiology Database
Classification (PBDB)Mollusca › Bivalvia › Myalinida › Inoceramidae· Paleobiology Database
Range (PBDB)227–66 Ma· Paleobiology Database
PBDB occurrences2595· Paleobiology Database

Photographs

Inoceramus — Inoceramus lamarckii Parkinson, 1819 (NHMUK PI OR 5842)
Inoceramus lamarckii Parkinson, 1819 (NHMUK PI OR 5842) — © The Trustees of the Natural History Museum, London, Natural History Museum (London) Data Portal, CC BY 4.0
Inoceramus — Inoceramus (NHMUK PI BB 59973)
Inoceramus (NHMUK PI BB 59973) — © The Trustees of the Natural History Museum, London, Natural History Museum (London) Data Portal, CC BY 4.0

Age

Formations

Elsewhere

Cite this article

Stratum Study. "Inoceramus" (Taxon). Stratum Study pack 2026.09, as of 2026-09-19. https://stratum.black/study/taxa/inoceramus. Accessed 2026-09-20.

BibTeX · CSL-JSON

@misc{stratum-inoceramus,
  title        = {Inoceramus},
  author       = {{Stratum Study}},
  howpublished = {\url{https://stratum.black/study/taxa/inoceramus}},
  year         = {2026},
  note         = {Taxon article, Stratum Study pack 2026.09, as of 2026-09-19; sources: stratum, pbdb, wikidata, commons, nhm. Accessed 2026-09-20.}
}

Citations carry the pack version and the article's as-of date so they resolve to the same text later. The facts themselves belong to the sources listed below; cite those for the science.