Name : Fossil Bird Wing Feather Age: Eocene Formation: Green River Formation Location: Kemmerer, Wyoming Size: Feather is 1.6 inches long! Is a very uncommon vertebrate fossil. This is a very fine fossil feather from the Eocene Fish Layers of Wyoming. Bird remains are quite rare in the fossil record – even individual feathers are highly uncommon, especially ones this large! This fossil feather is very easily seen and has very nice detail preserved. The distinct fossil has excellent natural color and contrast and is well showcased on the large plate of shale. This is a very impressive fossil feather from the Green River Formation.