Pennsylvanian Mire Forest

The images below the text show the fossil seed ferns that make up the fossil forest found in the mines. All pictures are looking up at the roof of the mine.



Fossil Plants - Seed Ferns

The seed ferns were a group of seed-producing plants with large fronds that, superficially, resembled the leaves of ferns (hence their name!). They have no close modern descendents.

The leaves of these plants were known prior to the discovery of their seed-bearing nature. In some species, the frond-like leaves could be more than 20 feet (7 m) in length. Trees have been found to be of two major growth forms: short, upright, free-standing forms, perhaps 15 feet (3 m) in height, and taller forms that were not self-supporting, but that formed tangles or thickets in which they leaned on one another and the large fronds were intertwined, lending support to the weak trunks.

Seed ferns were a diverse group of plants and so had many different kinds and sizes of reproductive organs. Their seeds ranged from small, perhaps the size of a modern "field pea", to quite large, roughly the size of, or even a little larger than, an avocado seed. (Click on image for larger view.)

Plant fossils above the Herrin coal from an underground coal mine





Laveineopteris rarinervis. Uncommon












Plant fossils above the Herrin coal from an underground coal mine





Neuropteris ovata. Common in parts of the mine and often forming dense mats of leaves.

Plant fossils above the Herrin coal from an underground coal mine

Plant fossils above the Herrin coal from an underground coal mine







possibly Odontopteris. This form was rare and only found in fragmentary preservation.











 

People & Places

Bill at Wabash

Calamites

closeup of a calamite

Cordaites

Cordaites leaves

Lycopsids

riola synchysidendron

Seed Ferns

seedferns

Tree Ferns

tree ferns

Ground Cover

groundcover

Back to Fossil Forest start page

Text by Scott Elrick, Image captions by Bill DiMichele, Images by Howard Falcon-Lang, Bill DiMichele and Scott Elrick


Updated 09/09/09 SDE

ILLINOIS STATE GEOLOGICAL SURVEY
E. Donald McKay, III, Interim Director

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