Fern

The fern is an ancient plant that has been in existence on the planet for hundreds of millions of year.
Learn more: https://en.wikipedia.org/wiki/Fern

Fern Fossil Imprints

Fern fossil imprints from the Pennsylvanian Period found in eastern Kentucky.

Fossilized Fern

Here is an image of an ancient fern. I am not sure if it is stored in coal or shale.