10" Cut & Polished Ammonite Fossil - Jurassic

This is a large, 10" wide, cut and polished ammonite fossil collected near Sakaraha in the Tulear Province of Madagascar. This colorful ammonite is Late Jurassic in age, or approximately 160 million years old. It's some genus of Phylloceratida, possibly Lobolytoceras.

The previously hollow chambers of the ammonite were replaced with a beautiful agate during the fossilization process. Some 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. These has been some repair work as these larger ammonites are almost always fractured while in the ground.

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

Ammonites were predatory mollusks that resembled squids with shells. These cephalopods had eyes, tentacles, and spiral shells. Though their shells resemble that of a nautilus, they are actually more closely related to living octopuses. Ammonites appeared in the fossil record about 240 million years ago, barely surviving several major extinction events. The last lineages disappeared 65 million years ago at the end of the Cretaceous.

Artist's reconstruction of an ammonite,  by Nobu Tamura
Artist's reconstruction of an ammonite, by Nobu Tamura
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DETAILS
SPECIES
Lobolytoceras?
LOCATION
Sakaraha, Tulear Province, Madagascar
SIZE
10" wide
ITEM
#172448
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