Alethopteris

Photographed by Michael A. Klimetz

[Frond Impression in Siltstone]

Pennsylvanian

PENNSYLVANIA

Photographed by Michael A. Klimetz

Alethoperis serlii

[Frond Impressions in Shale]

Pennsylvanian

St. Clair

PENNSYLVANIA

Alethoperis decurrens

[Frond Impression in Siltstone]

Carboniferous-Westphalian

Upper Silesia

POLAND

Photographed by Michael A. Klimetz