Eocene Green River Climbing Fern P-GR-16-005Lygodium kaulfussi Green River Formation Middle Eocene Lincoln County, Wyoming This specimen is the fertile branch of the plant. It is the spore bearing fertile leaves of the species. This is a relatively rare example. The fronds of the species are more commonly found. Lygodium is a relatively abundant fern that is found in the Green River Formation of Wyoming and Utah. It is an extant genus and if represented today by about 40 living species. The