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. The somewhat ornate cephalopod on the chain coral is an ancestor to the both the modern chambered nautilus and the cephalopod in the adjacent diorama scene. Some 300 million year old cephalopods have been found with the animal preserved. Tentacles show hooks, not suction disks, on their arms.
Dots mark Devonian coral-bearing exposures.
The asterisk marks the Falls of the Ohio. The small jawless fish in the foreground is an ancestor to lamprey. Fish are not preserved in local rocks, but no doubt swam in the ancient tropical seas. Fish developed nearly 120 million years earlier, but did not reach abundance until the Devonian period. This is a true patch reef.