Platycarya sp.
Green River Formation
Middle Eocene
Lincoln County, Wyoming

These beautiful leaves are from the Family Juglandaceae and are a relative to the walnut. The specimen has very good venation and the margin detail is well defined. This example is collected from the 18 inch layer. There is a fish coprolite on the right leaf.
Fossil examples of this group are represented today by some of our best known trees with many extant species. They usually have hard wood and some have slim elongate clusters of small flowers called catkins. Catkins belonging to this genus are also found in the Green River deposits.