Mazon Creek Plants

Plant Family Tree Diagram by Jessica Theodor ISM Assistant Curator, Geology

The Mazon Creek flora is incredibly diverse. Over 400 species from at least 130 genera have been identified from Mazon Creek nodules. However, the number of different kinds of plants represented is very difficult to determine. There are at least two reasons for this difficulty. The first reason is the convention among paleobotanists that separate plant parts receive different names. This procedure tends to inflate the number of plant names. The second reason is that paleobotanists are still trying to determine which taxa are valid.

The fossil plants discussed here are divided into four groups:

1. Lycopodium (Club mosses)
2. Equisetum (Horsetails)
3. Filicales (Ferns and seed ferns)
4. Gymnosperms (Gingkos)

Plants from the Mazon Creek deposit represent some of the plants that were living in the swampy lowlands near the shore and rivers. When they died they were washed into the bays and were preserved.

Many of the plants found in nodules were also important in producing the large Illinois coal deposits.