The fossils on the left and the modern shells on the right do share some features, but there are also major differences. The fossils and modern shells both are cone-shaped, but the cone is a very common shape in nature. We must look at the details.

The modern shells are hollow tubes, wrapped into a spiral, but the fossils don't spiral. Although many animals have shells that spiral, the fossil is not one of them. Inside the fossil are many ridges that divide the interior of the fossil into many segments, like slices of a pie.

Many of the fossils are connected at their base, forming a colony of individuals. The shells are not connected, but each was formed by a separate, free-living individual. Also, the fossil has ridges on its outside that form circles around it. The modern shell also has ridges on its outside, but they spiral the length of the shell, rather than forming circles like a belt.

The spiral shells on represent gastropods or snails, a common group of living mollusks. These specimens do not represent the same type of animal.