Bivalve oyster shell

Zig-zag growth lines

Here is an oyster with two shells that opened and closed. As you can see, the shell edges have a zig-zag pattern and can be mistaken for jaws. This pattern made the shells robust. The parallel lines above and below the ‘jaws’ are growth lines charting the life of the shell. Oysters are distinctive in that their shell is composed of many fine layers.

Find out more about bivalves on the molluscs pages.

Common name

Bivalve oyster shell

Scientific name

Rastellum carinatum

Type

Molluscs > Bivalves


Strata

Chalk, Lower

Time period

Upper Cretaceous

Age

95 million years

Where found

Unknown

Found by

Unknown

Museum

Dorset County Museum, Dorchester

Accession number

DCM.G.10031