Pennsylvanian
Wild Cow Member, Madera Formation
Los Lunes, NM, USA
90mm x 60mm slab.

Leaf. Fern.

Sphenopteris is a long-lived genus of seed ferns that appeared during the Devonian and survived into the Cretaceous.

This specimen was collected at a locality rarely seen on the market. You don’t see too many Pennsylvanian-age fossils from western North America.

The Pennsylvanian Period (Late Carboniferous) was a time of tropical climates across much of the world though ice was forming at the poles near its end.  Vast lowland swamps dominated much of what would become North America and Europe as the continents were drifting toward each other – destined to assemble into the supercontinent, Pangaea.