Field Book
PENNSYLVANIAN PLANT FOSSILS OF ILLINOIS
Charles Collinson
Romayne Skartvedt
Illinois State Geological Survey
Educational Series 6
STATE OF ILLINOIS
DEPARTMENT OF REGISTRATION AND EDUCATION
First edition 1960
Reprinted 1966
ILLINOIS STATE GEOLOGICAL SURVEY
URBANA ILLINOIS
John C. Frye, Chief
Printed by Authority of State of Illinois, Ch. 127, IRS, Par. 58.25.
Field Book
PENNSYLVANIAN PLANT FOSSILS OF ILLINOIS
Charles Collinson
Romayne Skartvedt
Illustrations by Marie E. Litterer
FOREWORD
This field book is intended to guide beginnersin their collection and generalclassification of plant fossils. It illustratesthe plant fossils most commonlyfound in Illinois and relates them to theplants of which they were a part. A listof publications that will furnish more detailedidentification of specimens is included. The bookhas been prepared in response to numerous inquiriesto the Illinois State Geological Surveyfrom amateur collectors.
Information has been drawn from numeroussources. The works of Hirmer, Janssen, Lesquereux,Noé, and Langford have been particularlyuseful.
We are especially indebted to Dr. RobertM. Kosanke, paleobotanist at the Illinois StateGeological Survey, and Dr. Wilson N. Stewart,professor of botany of the University of Illinois,for helpful suggestions and use of their libraries.
KEY TO PLANTS ILLUSTRATED ON TIME CHART
1. Foerstia. These fossils may be the earliest known occurrence of bryophytes, although some authors have referred them to the brown algae. After Dawson.
2. Psilophyton. A primitive vascular plant. After Dawson.
3. Lepidodendron. After Hirmer.
4. Sigillaria. After Hirmer.
5. Calamites. After Hirmer.
6. Sphenophyllum. After Fuller and Tippo.
7. Equisetum. The only living genus of scouring rushes. After Fuller and Tippo.
8. Megaphyton. An ancient true fern. After Hirmer.
9. Modern tropical tree fern. After Fuller and Tippo.
10. Medullosa. An ancient seed fern. After Stewart.
11. Williamsonia. An extinct cycad-like tree. After Sahni.
12. Cycas. A modern cycad. After Chamberlain.
13. Baiera. A fossil leaf genus of ginkgo, whose only living representative is the species