Fossil Fern | Alethopteris serlii | Pennsylvania

This 300 Million year old Pennsylvanian fossil fern, Alethopteris serlii is from the Pottsville Formation in St. Clair, Schuylkill Co. PA

Specimen measures approx. 8.5" x 5", 1.5cm thick

Alethopteris is a prehistoric plant genus of fossil Pteridospermatophyta (seed ferns) that developed in the Carboniferous period (around 360 to 300 million years ago).

It is in the family Alethopteridaceae. The genus Alethopteris is among the seed ferns (Pteridospermales), an extinct group of gymnosperms. Although their foliage resembled that of modern ferns, they reproduced by means of seeds. (Wikipedia)