This fossil, measuring 5.5 cm, is a nice example of an internal mold. It is a 80-135 million year old snail, classified a gastropod. Gastropoda are in the Phylum Mollusca which means these animals have soft bodies covered by a hard outer shell. The Lightening Whelk the Texas State Sea Shell, is an example of a modern-day gastropod.
Gastropods are univalves which means they have one shell.
Other types of soft bodied marine animals, like clams and oysters, have two shells, and are called bivalves . This fine looking snail was discovered by Ann, Cindy and Marcia January 2,000. They found the internal mold near Bandera, Texas, along with some clams and oysters.