Turtle coprolite 55mm curiosity from Wilkes formation, Salmon Creek, Toledo, Lewis & Cowlitz County, SW Washington State near Mount St. Helen's volcano. Dating back to the Miocene era, approximately 20 to 35 million years, the dung has been left behind by a prehistoric turtle. Under the right geological conditions for coprolite to be preserved, it has to be covered particularly quickly in an anoxic environment. Over time it is replaced by surrounding minerals, in this case siderite and limonite and permineralisation process's transform the dung into stone fossilised forever. Fossil remains such as plants, seeds, bark, teeth, claws and bones (dependent on the animal) can be discovered within the coprolite, which is a valuable indicator to the animals diet whether a herbivore or carnivore or what the animal dietary preferences were.
Coprolites helped scientists and researchers determine and understand diets of prehistoric animals, how their digestion worked. Also coprolite can be a great indicator to the seasonal changes that occurred millions of years ago once seeds and plant matter is microscopically analyzed.
humorous footnote, In the second image one may make out a poo-dles head and body shape. Historically Mary Anning first noticed stone pebbles in ichthyosaurs abdomens, once broken open she discovered fish bones of prey, this led William Buckland to coin the name coprolite in 1829.