Connecting the environment of the ancient past with the natural and cultural history of yesterday and today.



Featured Fossil


This page features a fossil with details about the specimen, its age,

where it was found, and a nugget of interesting information. Not every

specimen will be perfectly preserved - but all are a marvel of the natural world!

All geological time periods are represented.

Fluorite-encrusted Gastropod from Cave in Rock, Illinois

Fossil Type:

Fluorite-encrusted Gastropod




Ste. Genevieve


Basal Upper Mississippian


Cave in Rock, Hardin Co., Illinois


Steinkern or internal mold in chert with fluorite, this is an unusual fossil due to its mineralization. Anonymous collection. Mark Schneider photo.

Date Posted:

May 27, 2017


Archived Featured Fossils

Archived images are now arranged in each category by geological time period.

How to Submit a Featured Fossil

Created April 12, 2012