Coprolite

A coprolite is fossilized animal dung. Coprolites are classified as trace fossils as opposed to body fossils, as they give evidence for the animal's behaviour (in this case, diet) rather than morphology. The name is derived from the Greek words κοπρος / kopros meaning 'dung' and λιθος / lithos meaning 'stone'. They were first described by William Buckland in 1829. Prior to this the 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.

Research value
By examining coprolites, paleontologists are able to find information about the diet of the animal (if bones or other food remains are present), such as whether or not it was a herbivore, and the taphonomy of the coprolites, although the producer is rarely identified unambiguously, especially with more ancient examples. In one example these fossils can be analyzed for certain minerals that are known to exist in trace amounts in certain species of plant that can still be detected millions of years later. In another example, the existence of human proteins in coprolites can be used to pinpoint the existence of cannibalistic behavior in an ancient culture. Parasite remains found in human and animal coprolites have also shed new light on questions of human migratory patterns, the diseases which plagued ancient civilizations, and animal domestication practices in the past (see archaeoparasitology and paleoparasitology).

Recognizing coprolites
The recognition of coprolites is aided by their structural patterns, such as spiral or annular markings, by their content, such as undigested food fragments and by associated fossil remains. The smallest coprolites are often difficult to distinguish from inorganic pellets or from eggs. Most coprolites are composed chiefly of calcium phosphate, along with minor quantities of organic matter. By analyzing coprolites, it is possible to infer the diet of the animal which produced them.

Coprolites have been recorded in deposits ranging in age from the Cambrian period to recent times and are found worldwide. Some of them are useful as index fossils, such as Favreina from the Jurassic period of Haute-Savoie in France.

Some marine deposits contain a high proportion of fecal remains. However, animal excrement is easily fragmented and destroyed, so usually has little chance of becoming fossilized.

Coprolite mining
In 19th century England, coprolites were mined on an industrial scale for use as fertilizer due to their high phosphate content. The extraction occurred over the east of England, centered around Cambridgeshire and the Isle of Ely with its refining being carried out in Ipswich by the Fison Company. Today, there is a Coprolite Street near Ipswich Docks where the Fisons works once stood. The industry declined in the 1880s but was revived briefly during the First World War to provide phosphates for munitions.