Fossil Pterocarya (Walnut) Leaf - Green River Formation

This is a fossil leaf from Pterocarya roanensis, a type of walnut. It is Eocene in age and comes from the Green River Formation. It has nice dark preservation, which make the fine details harder to see.

It comes the Green River Formation and the area in Uintah County, Utah. This is the same formation that is famous for producing well preserved fish fossils, but a different member and location.