3.6 Inch Cleoniceras Ammonite (Half)

Here is large 5.87 inch wide, 110 million year old ammonite fossil from Madagascar which has been cut in half and polished. Some of the chambers are preserved as pockets of calcite crystals. The reverse side is also polished and shows some of the beautiful "oak leaf" sutures of the Cleoniceras genus. This is truly a natural piece of art.

About Ammonites

Ammonites were predatory, marine mollusks that thrived during the Paleozoic and Mesozoic eras, particularly in the Jurassic and Cretaceous periods, before going extinct around 66 million years ago. These creatures are characterized by their coiled, spiral shells, which resemble the modern-day nautilus. Ammonite shells were divided into chambers; as they grew, they built new chambers and sealed off the old ones. These chambers were filled with gas, which helped them control buoyancy in the ocean.

The outer shell of ammonites often displays intricate ribbed or ridged patterns and their fossils sometimes show a wide range of beautiful colors due to mineralization over time. The shells fossilized well, making ammonites abundant in the fossil record.. In addition to being popular in fossil collections, ammonites are valuable in geological studies, as they serve as index fossils, helping scientists date rock layers and understand the Earth's prehistoric environments.

Artist's reconstruction of an ammonite, by Nobu Tamura

More about ammonites