Dinosaur Coprolite from Utah. These agatized pieces are fossilized dinosaur dung.
A coprolite (also known as a coprolith) is fossilized feces. Coprolites are classified as trace fossils as opposed to body fossils, as they give evidence for the animal’s behavior (in this case, diet) rather than morphology. They were first described by William Buckland in 1829. Before this, they were known as “fossil fir cones” and “bezoar stones”. They serve a valuable purpose in paleontology because they provide direct evidence of the predation and diet of extinct organisms. Coprolites may range in size from a few millimeters to over 60 centimeters.
Coprolites, distinct from paleofeces, are fossilized animal dung. Like other fossils, coprolites have had much of their original composition replaced by mineral deposits such as silicates and calcium carbonates. Paleofeces, on the other hand, retain much of their original organic composition and can be reconstituted to determine their original chemical properties, though in practice the term coprolite is also used for ancient human fecal material in archaeological contexts.