Figure 4. Cretaceous Oysters

Numerous shells of the oyster Exogyra costata fill this outcrop of the Prairie Bluff Chalk at Moscow Landing on the Tombigbee River in Sumter County. Oyster shells are common fossils in the Cretaceous sedimentary deposits in Alabama.

Fossilized shells embedded in exposed rock, with a measurement scale at lower left.
Photograph by David R. Schwimmer, all rights reserved
Fossilized shells embedded in exposed rock, with a measurement scale at lower left.