Above is an image of a seed fern plant fossil called Odontopteris aequalis. This plant fossil dates to the Carboniferous (Pennsylvanian) Period. It was found Mazon Creek, Illinois, USA. Like most fossils found at this locality, it was inside a nodule.
The fossil was on display in the Evolving Planet section of The Field Museum of Natural History in Chicago Illinois, USA as of August 2020. Accession number is PP31097. They have quite an extensive collection of Mazon Creek fossils at the exhibit.
The Field Museum produced a visual PDF of some of the fossils found at Mazon Creek. It can be found at this link:
