Pyritized (Pleuroceras) Ammonite Fossils - Germany

These are two beautifully pyritized Pleuroceras ammonite fossils collected near Forcheim, Germany. They're Jurassic, Pliensbachian stage or approximately 185 million years old. You can feel the heft of the iron pyrite in the specimen when you hold it in your hand.

Ammonites were predatory mollusks that resembled a squid with a shell. These cephalopods had eyes, tentacles, and spiral shells. They are more closely related to a living octopus, though the shells resemble that of a nautilus. True ammonites appeared in the fossil record about 240 million years ago. The last lineages disappeared 65 million years ago at the end of the Cretaceous.

What an ammonite would have looked like while alive.

More about ammonites