TRILOBITES are an extinct group of arthropods and possessed a head, thorax and tail. Exceptionally-preserved trilobites also show legs and antennae. Isopods, commonly known as sowbugs or pillbugs, are a modern arthropod that resembles trilobites in many ways. All trilobites lived in seawater. Most were crawlers upon the seafloor, and some could also swim through the water or burrow into sediment. Since trilobites are extinct, interpretation of their feeding habits is difficult. Many may have been scavengers of dead organisms, and some may have been predators, grazers, or filter-feeders.
At least 19 species of trilobites lived as dwellers in the Silurian reefs of Wisconsin. Four of these species, shown above, are present in the diorama.