2.5" One Side Polished, Pyritized Fossil, Ammonite - Russia
This is a gorgeous pyritized ammonite of the genus Quenstedticeras. It was collected from a Middle Jurassic age deposit along the banks of the Volga River near Saratov, Russia. One side of the ammonite has been polished to a mirror-finish, revealing the pyrite replaced/lined chambers. The opposite side of the ammonite has been left rough to display the stunning iridescent shell.
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.