Fossil poo is easy to identify. Why? Because it looks just like poo!
The proper name for fossil poo is coprolites. ‘Copro’ comes from the Greek word for ‘dung’, and ‘lite’ from the Greek for ‘stone’.
They are often packed with fish scales and even bone.
This specimen is from a shark. You can see the coils left as it travelled through the gut.
For poo to fossilise, it needed to fall onto a still seafloor so it didn’t disintegrate. There it gradually hardened while being buried by sediments, so it kept its shape.
The 1800s geologist William Buckland was so fascinated by fossil poo that he made a table top out of it! The coprolites in the table have mineral veins coming out of them which look like legs, leading to the name ‘beetle stones’.
See these coprolites at Allhallows Museum and the table at Lyme Regis Museum.