Coprolite

Coprolite is known as a trace fossil which gives an indication of a creatures habits and habitat. It's basically fossilised feces, the actual material being replaced by calcium carbonates and silicates. The term coprolite was first used in 1829 when researchers realised what the distinctive material was discovered within the 'digestive area' of animal fossil remains.

Coprolite was once heavily mined in the late 1900's due to it's chemical composition mainly phosphates.