PHYLUM MOLLUSCA, CLASS GASTROPODA
The snails are single-valved molluscs that are trochospirally coiled (like a screw). As with the clams, the shells are made of aragonite and so are usually lost, with preservation therefore usually as molds. The picture on the left is of a Recent "marlinspike" (Terebra maculata) from the Indo-Pacific ocean. That on the right is of an unidentified Oligocene species from near Bridgeboro, GA. It is unidentified precisely because it is an internal mold. Both scale bars are 1cm. (Photos by B. Carter.)