Above is an image of part of a seed fern frond plant fossil called Neuropteris inflata (Lesquereux). This plant fossil dates to the age Moscovian/Desmoinesian of the Carboniferous (Pennsylvanian) Period between 354 and 290 million years ago. It was found Mazon Creek, Illinois, USA. Like most fossils found at this locality, it was inside a nodule. The layer to fossil was found is the Francis Creek Shale.
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 P30763. 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:
