Coral does not grow well in cool water and therefore does not form reefs outside of the tropics. Looking at the diorama, corals dominate the Louisville and Jeffersonville Limestone scenes, but are less important in the North Vernon Limestone where brachiopods and crinoids are more numerous. The Silurian rocks are characterized by over 150 fossil species. The diorama recreates nearly 200 species of fossils. This is a small representation of the living ecosystem, where only a minute number of organisms were actually preserved.
Scientists estimate only one percent of the species of plants and animals are preserved as fossils.
A replica can be examined more closely on the wall directly across from the diorama. Individuals forming the colony are linked together like a chain, hence its nickname. A variety of other animals may be found in the Silurian rocks, recreated in the diorama. They are similar to crinoids in the Devonian diorama, but have fewer arms. Unlike corals, the arms are not soft, consisting of hard skeletal plates.