5.4 Inch Polished Ammonite - Red Iredescents

Here is a gorgeous polished Cleoniceras ammonite fossil from the Cretaceous deposits of Madagascar. It's 5.4 inches in diameter and has some great fiery red iredescent hues when you catch it in the right light.

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.

Artists reconstruction of an ammonite. By Nobu Tamura

More about ammonites