I just love ammonites! They are such great animals.... Shame they all died. We covered them quite extensively in paleontology classm along with the other Cephalopods. They were so much better when they all had shells since the turn I to such nice fossils. Fossilization isn't perfect though. When fossils are preserved they can lose some of their details, so for ammonites that have almost fractal like shapes in their insides, some of the details are lost.