Lithophaga nuda

Phylum Mollusca
Class Bivalvia

(Scale bar is 1 cm)

Species of Lithophaga are common in Paleogene rocks of the southeast, but only in association with corals or other organisms with large stony skeletons. These clams bore into hard substrates. They are usually preserved as internal molds of the shell itself or external molds in the substrate. The photo shows the former mode of preservation on the right, and on the left shows the inside of part of a broken algal rhodolith from the Bridgeboro Limestone with a mold of the clam inside it.

Because corals and rhodoliths are most common in the Bridgeboro, Lithophaga is most common in that unit as well, and L. nuda is the most common species. Another species (L. gainesensis) is common in rhodolith rich facies of the Paleocene Clayton Formation, and yet other species occur in the Ocala Limestone. These species can be difficult to distinguish, since they are preserved as molds, and their potential use for correlation depends upon specific identification.

Reef-building corals (with their symbiotic algae) and rhodoliths both require shallow clear water, so rhodoliths are most often found in that sort of setting. However, the clams themselves do not require such an environment, and could be found in rock bottoms at any depth.


AGE: EARLY OLIGOCENE

FORMATION: BRIDGEBORO LIMESTONE and RESIDUUM

RETURN TO BRIDGEBORO LIMESTONE

RETURN TO OLIGOCENE RESIDUUM

RETURN TO TAXONOMY

RETURN TO FOSSILS HOMEPAGE