Jurassic Ammonites (Stephanoceras) - Fresney, France

Here is a beautiful association of Middle Jurassic marine fossils, collected from Fresney, France. There are two Stephanoceras ammonites (3.2" and 1.75") that are next to a bivalve fossil and a small unidentified ammonite. The piece has been wonderfully prepared to create this aesthetic display.

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