11.1" Cut & Polished Ammonite Fossil - Jurassic

This is a large, 11.1" wide, cut and polished ammonite (Perisphinctes?) fossil collected near Sakaraha in the Tulear Province of Madagascar. This colorful ammonite is Late Jurassic in age, or approximately 160 million years old.

The previously hollow chambers of the ammonite were replaced with a beautiful agate during the fossilization process. Marny of these chambers are still partially hollow and lines with druzy crystals. The ammonite was cut in half and polished revealing the inner chamber structure of this ancient marine animal.

Both halves are included and they come with a pair of display stands.

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
Perisphinctes?
LOCATION
Sakaraha, Tulear Province, Madagascar
SIZE
11.1" wide (each half)
ITEM
#183362
GUARANTEE
We guarantee the authenticity of all of our specimens.