Flattened Spiral Coprolite

This particular specimen was sold as a dinosaur coprolite. That is because observers often mistake the texture found on the surface as fish scale inclusions. However, these are actually impressions left by intestinal folds within the spiral valve of the fish that expelled it. Magnified images of these folds are shown in the last few photos. It is hard to see the spiral structure in this example because it is a bit squished.