Lygodium fruiting organ

Early Eocene

Green River Formation

Kemmerer, WY USA.

Rare 11mm spore-bearing organs on 52mm slab from the “split fish” layers.

Plant.

Lygodium is a genus of climbing fern that dates back to the Late Cretaceous of New Jersey and Germany.  It spread worldwide during the Cenozoic.

Lygodium lives in tropical and warm temperate regions today.  Its presence in the Early Eocene of Wyoming testifies to a much wetter and milder climate there at that time.