Here is an amazingly well preserved Mazon Creek Single Pecopteris Leaf. It is from the famous Lagerstatte of Central Illinois. There are several species of Ferns found in the fossil floral record.
A Lagerstatte is a German word meaning storage place and we have used it to describe this area that is a “storehouse” of exceptionally preserved flora and fauna. The Carboniferous Period of Illinois was mostly a hot steamy jungle and swamps. The plants and animals were buried in sediment without much Oxygen and began to fossilize.
The Mazon Creek Single Pecopteris Leaf fossil was found within and “Ironstone” nodule. These nodules when broken open display these exceptionally preserved fossils.
This Mazon Creek Single Pecopteris Leaf is beautifully displayed in this black collectors case. Because the fern leaves and ironstone nodule are so brittle they are protected in this case. Often the “Freeze-thaw” method is used to break them open but the natural cycle of freeze thaw outside also works. They are soaked in water because that allows allows water to infiltrate the rock along the line of the fossil. But then freezing water expands and breaks it open along that line. If that doesn’t work after a while, a gentle whack with a hammer can help.
The central part of Illinois is famous for these nodules with fossils inside. Because of coal mining activity they were brought to the surface. They discarded the nodules because they had no useful purpose. It is in these nodules that Mazon Creek Single Pecopteris Leaf may be found.