| Pennsylvanian
Subclass Apterygota Order Monura
Mazon Creek, Illinois |
Pennsylvanian
Class Sarcopterygii, Subclass Dipnoi
Mazon Creek, Illinois |
Silurian
Order Phacopida
Family Phacopidae
Niagaran Limestone, Illinois
|
Pennsylvanian
Cycadophyta
Medullosales
Mazon Creek, Illinois |
