A large Parkinsonia Ammonite on Rock (France). Ex. Niagara Falls Museum collection. Ammonites are more closely related to a living octopus, though the shells resemble that of a nautilus. Ammonites first appearing in the fossil record 240 million years ago, descending from straight shelled cephalopods. The last lineages disappeared 65 million years ago at the end of the Cretaceous.
6 in. diameter x 3 in. deep