A collection of coprolite at a fossil fair. Coprolites are the fossilized feces of prehistoric animals. As it is very rare that a sample can be accurately related to a specific genus of animal, coprolites are classified according to their own taxonomy. Particularly well-preserved examples may reveal data on the animal's diet, especially in more recent mammals such as bears and cave lions. Fossil fairs provide a forum for amateur and commercial collector to trade in prehistoric remains. Although frowned upon by many academics, amateur paleontologists have often made finds of previously unknown species. (1991)