Stacks Image 18
Gastropods are a successful group of moluscs with a very good fossil record. Earliest recorded gastropods have been found on Cambrian rocks (more than 500 million years ago). Currently, gastropods live no only in the sea, but also in fresh water and on land.

Although some gastropods lack hard parts (slugs), most of them have coiled shells that can be preserved as fossils. Due to this particular geometry, shells of gastropods have two distinctive cross sections: cross sections parallel to the axis exhibit an elongated form with a sharp point, whereas cross sections perpendicular to this axis are normally rounded.
Stacks Image 5