2.3" Polished Agatized/Pyritized Ammonite Fossil Slab - Germany

Polished Agatized/Pyritized Ammonite Fossil Slab - Germany #125416

This is a polished slab from the Holzbachacker clay pit that contains both agatized and pyritized ammonite (Pleuroceras spinatum) fossil segments. It's Jurassic, Pliensbachian stage or approximately 190 million years old. One side of this slab has been left unpolished, revealing the pyrite formations and a small bivalve.

This specimen stands nicely on its own.

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