Cladoceramus

Cladoceramus Temporal range: Late Turonian-Santonian ~89.8–83.6  Ma PreꞒ Ꞓ O S D C P T J K Pg N
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Bivalvia
Order:	Pteriida
Family:	† Inoceramidae
Genus:	† Cladoceramus Seitz 1961
Species
C. undulatoplicatusRoemer 1852

Cladoceramus is an extinct genus of fossil marine pteriomorphian bivalves that superficially resembled the related winged pearly oysters of the extant genus Pteria . They lived in the Santonian stage of the Late Cretaceous.

Description

Adult shells of Cladoceramus are small to very large size (more than 1 metre [3 ft 3 in] in length). ^[1] Many species with fine, discrete, juvenile ornamentation on umbo, consisting of closely and evenly to subevenly spaced raised concentric growth lines without rugae. Posterior auricle well-defined, triangular, separated from disc by auricular sulcus; a post-umbonal sulcus occurs in some species, as do very small anterior auricles ("ears"). ^[1]

Biostratigraphic significance

The first appearance of the species Cladoceramus undulatoplicatus marks the beginning of the Santonian stage.

Distribution

Fossils of the genus have been found in: ^[2]

• Matulla Formation, Egypt

United States

• Forbes Shale, California
• Smoky Hill Shale, Niobrara Formation, Colorado and New Mexico
• Austin Chalk, Texas
• Mancos Shale, Wyoming

References

1. 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
2. Cladoceramus at Fossilworks.org