4" Polished Cretaceous Ammonite (Cleoniceras) Fossil - Madagascar

This is a 4" wide polished ammonite of the genus Cleoniceras, collected in Madagascar. It is absolutely gorgeous, displaying a distinctive "oak-leaf" suture pattern on the surface. This 110 million year old ammonite is truly a natural work of art, displaying beautifully on the included acrylic stand.

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
Artist's reconstruction of an ammonite, by Nobu Tamura

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DETAILS
SPECIES
Cleoniceras sp.
LOCATION
Ambatolafia, Mahajanga Province, Madagascar
SIZE
4" wide
ITEM
#305904
GUARANTEE
We guarantee the authenticity of all of our specimens.