Vertebrate fossils
Coprolites (fossil dung)
Fossilized poop. Less glamorous than teeth but tells us what predators were eating — coprolites often contain shark scales, fish bones, and shell fragments. Common in phosphate spoil piles and Aurora-area gravel.
How to spot it
- ▸Sausage-, spiral-, or pellet-shaped lumps
- ▸Phosphate-rich — often gray, brown, or black with a chalky surface
- ▸Sometimes preserve a spiral 'screw' pattern from the shark's intestinal valve
- ▸Heavy for their size; sometimes show inclusions of bone or scale
Easy to confuse with
- ·Phosphate nodules (similar texture but no shape pattern)
- ·Iron concretions (denser, more rust-colored)
Reported at these sites
About the category
Bones, vertebrae, and ear-bones from extinct and modern marine vertebrates. Heavier and denser than rock of the same size, with a tell-tale honeycomb internal structure when broken.