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.


 

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





Updated 03/20/12 SDE

ILLINOIS STATE GEOLOGICAL SURVEY
615 E. Peabody
Champaign, IL 61820
217-333-4747
info@isgs.illinois.edu

Terms of use         Privacy Statement

© 2012 University of Illinois Board of Trustees. All rights reserved.
For permissions information, contact the Illinois State Geological Survey.