When they died sediments filled up the empty shells and the sediments eventually turned to stone. The shells gradually dissolved leaving the stone molded to the shape of the inside of the shell.
Beach of central Texas lake.
Gastropod means "stomach foot". These animals have a single muscular foot. Gastropods are the largest class of mollusks. They are called univalves because they build a single coiled shell to protect their soft bodies. Ancient fossilized gastropods are related to living gastropods of today like snails. Gastropods can be carnivorous (meat-eaters) or herbivorous (plant eaters). Their tongue is covered with thousands of tiny teeth to tear apart food.
Lat: 31.11, Long: -97.50
Spotted on May 12, 2013
Submitted on May 16, 2013