From Encased Ferns to Majestic Amber
Ancient Forests
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An often overlooked group of organisms that are just as important, if not more, than animals are plants. Even today, much of the plant life we see mirrors what was seen millions of years ago, demonstrating how crucial plants are to maintain biodiversity. Plant fossils, in fact, have served monumental purposes in understanding the prehistoric world from providing evidence of climate patterns to preserving incredible remains in amber.
Check out the Ancient Forests gallery!
Life in Concretions
Around 309 million years ago during the Middle Pennsylvanian, northeastern Illinois was much different than it is today. Back then, it was located near the equator with a tropical climate that allowed for immense biodiversity. With swampy forests and marshes, this area was home to widespread flora (plants) and fauna (animals). Today, this place is now known as Mazon Creek.
Mazon Creek is a famous lagerstätte, a site known for remarkable preservation in fossils, often including soft tissues and the most delicate of features. Fossils from Mazon Creek are found in iconic ironstone concretions, which are compact matters of rock that are usually ovoid in shape. The incredible preservation found with these fossils have yielded a great understanding of the complex ecosystem that existed back then along with details that give insights into how these creatures looked. A classic example is the bizarre Tully monster, the state fossil of Illinois, with its eye bar and long proboscis.
Let us explore the life hidden within Mazon Creek's concretions.
Flourishing Ferns
Paleobotanists currently have named over 400 species of plants that make up the Mazon Creek flora, a number which shows how vibrant with life Mazon Creek was all those years ago.
Ferns were especially commonplace in this humid environment. This particular specimen is part of the genus Pecopteris, a type of fern leaf that first appeared in the Devonian but thrived during the Pennsylvanian. The swamps of Mazon Creek provided the perfect conditions for Pecopteris and a multitude of other ferns and plants to flourish and dominate the landscape.
With this specimen, you can see the entirety of a frond, the leaf of a fern. Try comparing this frond to a modern fern for similarities and differences!
The specimen to the right is an example of another frond that existed in Mazon Creek. With the unique golden color, you can better see the remarkable details of this fern with the frond's veins and patterns that make it impossible to think this lived over 300 million years ago.
