This Specimen has been sold.
3.9 Inch Ammonite - Polished One Side - Iridescent Other
This is a very cool ammonite fossil from the Middle Cretaceous of Madagascar. One side has been highly polished while the reverse side is covered with a silver Iridescent shell. Take a look at the photos to see the contrast. This specimen would make a great display on the included stand.
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 ago and they barely survived several major extinction events. The last lineages disappeared 65 million years ago at the end of the Cretaceous.