Ammonites were shelled cephalopods that died out about 66 million years ago. Fossils of them are found all around the world, sometimes in very large concentrations. The often tightly wound shells of ...

If you’ve ever been in a shop that sells fossils — the natural history museum gift shop, the nature store in the mall, and so on — you’ve probably seen an ammonite. Its chambered coils make a distinct ...