Jurassic Ammonites (Stephanoceras) - Fresney, France

Here is a beautiful association of Middle Jurassic marine fossils collected from Fresney, France. Two Stephanoceras ammonites (3.2" and 2.3") are sitting near an unidentified bivalve fossil. The piece has been wonderfully prepared to create an aesthetic display.

Ammonites were predatory cephalopod mollusks that resembled squids with spiral shells. They are more closely related to living octopuses, though their shells resemble that of nautilus species. True ammonites appeared in the fossil record about 240 million years ago during the Triassic Period. 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