Large, 4.8" Coprolite (Likely Crocodile) - Green River Formation
This is a large, 4.8" long coprolite (fossil poop) from the Green River Formation of Wyoming. Given it's huge size this most likely was produced by a large crocodile. It's fairly 3d and nicely prepared to remove the rock surrounding it. It's rare to find coprolites this large in the formation.