Fossil Fern | Diplazites unita | Illinois

Diplazites unita
Pennsylvanian
Carbondale Formation
Braidwood, Illinois

Specimen approx. size: 3.5" x 0.75"

Matrix approx. size: 3.5" x 1.375

*Note: the darker half is much thinner than the lighter half.

Diplazites unita is a type of ancient fern that lived during the Late Carboniferous, around 307 million years ago. Their fossils are commonly found in the Carbondale Formation of Illinois, USA. 

Diplazites unita belongs to the class Filicopsida, which includes ferns. It's a member of the extinct order Marattiales, which grew as tree ferns.
The fern had pinnate leaves with specific vein patterns and sporangia on the underside. Mature pinnules are separate and broadly attached to the rachis, with a strong midvein extending nearly to the apex. These ferns likely grew in swampy areas, rapidly occupying disturbed soil away from flooded habitats. They could reach heights of up to 30 feet, with trunks covered in a wide, fibrous root mantle.