The armored fish in the diorama is a distant relative to the giant arthrodire in the lobby exhibit. The needle-like teeth of one coelacanth can be found in the some layers of the Jeffersonville Limestone. The North Vernon Limestone section of the diorama represents a rock formation that is found on the far end of Goose Island, near the upper gates of the dam. The best exposures of this rock lie to the northeast of the Falls near Charlestown and Sellersburg, Indiana. This formation has a different variety of fossils compared to the underlying Jeffersonville Limestone.
Crinoids are more abundant and diverse.
Corals are still common, but less diverse. Mollusks, especially snails and clams, are more common. Echinoderms in the diorama include the crinoids and blastoids. Note the crinoid stalk with the spine-like flanges. The small purplish crinoid is best known from the grappling hook-like holdfast, which kept it from being swept away by currents.