Janice found two seashells when she went to the beach. They appear to be almost the same size, but they have different shapes. How could she figure out if their volume is the same?

During the paleolithic, hominins grouped together in small societies such as bands, and subsisted by gathering  plants  and fishing, hunting or scavenging wild  animals. the paleolithic is characterized by the use of knapped stone tools, although at the time humans also used  wood  and bone tools.