The Paleontology of North America

Bivalves from North America

> Bivalves | Cephalopods | Gastropods | Other Molluscs

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Pycnodonte (Gryphaea) convexa
Pycnodonte (Gryphaea) convexa
© 2003 Otto S. Zapecza

Buchia acutistriata
Buchia acutistriata
© 1998 Dr. Richard Paselk, Humboldt State University Natural History Museum

Musculinium partumeium
Musculinium partumeium
© 2005 Yale Peabody Museum

What are Bivalves? Bivalves are molluscs with a shell made of two interlocking pieces (valves) made of calcium carbonate. They can be found in many different freshwater and marine environments, such as lakes, tide pools, reefs, and hydrothermal vents. Some bivalves attach themselves to hard surfaces (oysters, mussels), a few species can swim (scallops), but most bury or anchor themselves into soft sediment. Partly because they have a hard shell, and partly because they are so numerous, the fossil record of bivalves is fairly good and extends back to the Cambrian.

First known fossil occurrence: Cambrian.

Last known fossil occurrence: Quaternary. This group has living relatives.

Fossils through time:
Choose a time period to see what life was like:

Quaternary
Tertiary
Cretaceous
Jurassic
Triassic
Permian
Carboniferous
Devonian
Silurian
Ordovician
Cambrian
Precambrian