Pictures of fern fossils from St. Clair, Pennsylvania. These plants grew in the Late Carboniferous or Pennsylvanian Period and can be found in the Llewellyn Formation. Fossils compliments of Shamalama.
St. Clair is famous for the white appearance of their plant fossils which caused by aluminum silicate or pyrophyllite. This first fossil is Alethopteris.
Modern fern image to use as comparison to fossil.