Now I could have had fun with the above title BUTT but it seemed too easy (ahem). Anyways Donald let me show his coprolite collection, if anyone wants to add anything, comment away!
Coprolites are fossilized faeces or animal dung. They form an important class of objects studied in the field of paleontology.
The name is derived from the Greek words κοπρος/kopros meaning ‘dung’ and λιθος/lithos meaning ‘stone’.
A coprolite is a type of trace fossil and can vary in size from the tiny piles of excreta from a worm that lived some 500 million years ago to the large droppings of crocodiles, dinosaurs or mammals. Typical sizes vary from less than 5 mm (0.2 inches) to 5 cm (2 in), although they may exceed 30 cm (12 inches) in length. There is a large variety of shapes: cigar-shaped, lens-shaped, kidney-shaped, cone-shaped, round, oval, cylindrical or spiral-shaped, depending upon the type of animal which produced them, although, as with other trace fossils, the specific animal is usually not known. Analysis of human coprolites by archaeologists can provide information on the diet and health of a study subject.
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 can, in some cases, be possible to determine 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.
Lots of great pictures here also: http://www.oceansofkansas.com/Coprolite.html