Coprolite

They serve a valuable purpose in paleontology because they provide direct evidence of the predation and diet of extinct organisms.

Like other fossils, coprolites have had much of their original composition replaced by mineral deposits such as silicates and calcium carbonates.

These observations by Anning led the geologist William Buckland to propose in 1829 that the stones were fossilized feces and name them coprolites.

[11] Further, coprolites 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.

[14] The recognition of coprolites is aided by their structural patterns, such as spiral or annular markings, content, undigested food fragments, and associated fossil remains.

Coprolites have been recorded in deposits ranging in age from the Cambrian period[15] to recent times and are found worldwide.

The major area of extraction occurred over the east of England, centred on Cambridgeshire and the Isle of Ely[19][20] with its refining being carried out in Ipswich by the Fison Company.

A large coprolite of a carnivorous dinosaur found in Harding County, South Dakota, US
A large Miocene coprolite from South Carolina, US
Coprolites found on the Blahnita riverbed, Romania, showing a seed inclusion (right specimen)
A large coprolite from South Carolina, US
Age: White River Oligocene; Location: Northwest Nebraska; Dimensions: Varies (25 mm × 20 mm); Weight: 8-10 g; Features: Many small inclusions and one has a complete toe bone from a small deer called a leptomeryx.
A Miocene pseudocoprolite from Washington state. They are commonly mistaken for coprolites because of their appearance and shape; they are actually of inorganic origin. Scale in mm. See Spencer (1993).