5.1" Fossil (Jeletzkytes) Ammonite - South Dakota
This is a gorgeous 5.1" wide Jeletzkytes nebrascensis ammonite specimen collected from the Fox Hills Formation of South Dakota. Portions of the shell have chipped away from the ammonite, though most of the shell is intact and exhibits beautiful iridescence. A small amount of rock has been left attached to the ammonite. Comes with an acrylic display stand to assist with presentation.
These 70 million year old ammonites lived when South Dakota was a shallow inland sea. It was found preserved in a concretion that was split open. It then had to be hand prepared to remove the hard rock surrounding it from the shell, a very time consuming task.
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. Ammonites appeared in the fossil record about 240 million years. The last lineages disappeared 65 million years ago at the end of the Cretaceous.