Purchased in a small rock shop in South Dakota, not much is known about this coprolite. It is believed to have originated from Montana. The center is fairly homogenous with no visible inclusions. Because of the acidity of their digestive systems, crocodilian coprolites rarely contain inclusions. They have also been known to produce nipple-shaped sphincter marks. Based on this, a croc is a likely candidate if if was found in Montana.
If Jesper Milàn's study on modern crocodilian scat holds true for prehistoric croc coprolites, this poopetrator would have been around 9.3 feet (283.3cm) long!