Madagascar White Spine Ammonite Fossil – Early Cretaceous Cleoniceras

A Stunning White Spine Ammonite from Ancient Madagascan Seas

Species: White Spine Ammonite (Cleoniceras sp.)

Age: Early Cretaceous Period, approximately 110 million years ago

Location: Near Sakaraha, Madagascar

Ammonite Size: 53mm x 63mm x 17mm (approximately)

Weight: 85 gram

This authentic White Spine Ammonite from near Sakaraha, Madagascar is a beautifully preserved relic of ancient tropical seas that existed over 100 million years ago. These striking fossils are recognised for their elegant spiral shells and distinctive pale calcite spines or ribbing that once strengthened and protected the animal’s shell. Ammonites were marine cephalopods — intelligent, tentacled molluscs that swam freely through prehistoric oceans. Although long extinct, their closest living relatives today are the nautilus, squid, octopus, and cuttlefish, all members of the cephalopod family.

White Spine Ammonites lived during the Early Cretaceous Period, around 110 million years ago, when Madagascar was submerged beneath warm, shallow seas rich in marine life. Fine sediment settled gently on the seafloor, rapidly burying shells after death and creating ideal conditions for fossilisation. Over millions of years, mineralisation preserved the delicate structure of the shell, including its intricate ribbing and internal chambers. The region around Sakaraha is world-famous for ammonite fossils because these ancient seabeds were later uplifted by geological activity, bringing perfectly preserved marine life to the surface where it can be discovered today.

Ammonites are incredibly important in the fossil record because they evolved rapidly and existed in enormous variety across the globe. Their distinctive shell forms allow scientists to date rock layers with remarkable accuracy, making them one of the most valuable index fossils in geology. Each specimen is not just a beautiful natural object — it is a scientific time marker that helps reconstruct ancient oceans, shifting continents, and the evolution of marine life.

This Madagascan White Spine Ammonite is more than a fossil — it is a preserved fragment of Earth’s distant past, capturing the form of an ancient ocean dweller whose legacy still helps scientists understand the history of life on our planet.

Add this iconic spiral of prehistoric life to your collection today!