Pyritized Ammonite Pair

This incredible Ammonite Pair With Pyritization (Speetoniceras sp.) was collected on the banks of the Volga River in Russia and dates to the Jurassic Period — 201 to 145 million years old. It's a spectacular specimen: the inner chambers of both halves are lined with sparkling pyrite crystals. It’s certainly a stunning piece of natural history!

Ammonites have intrigued and fascinated humans for thousands of years. Many cultures - from Australian aboriginals to the ancient Egyptians - collected and treasured these prehistoric and beautiful fossils. Perhaps their lure has something to do with the Fibonacci spiral pattern of their shell, which mirrors the galaxies. Ammonites belong to the Mollusca Phylum in a Class known as Cephalopods – “head-footed” creatures such as octopus and squid. They swam in ancient oceans from 400 million years ago, to their extinction, along with the dinosaurs, 65 million years ago.

Ammonites were free floating invertebrates that were attacked by plesiosaurs and mosasaurs, two groups of gigantic marine reptiles. One way that ammonites could avoid an attack was to quickly change their buoyancy levels, zig zagging and sinking rapidly. These incredible prehistoric animals ranged in size from tiny species only a few centimetres in diameter to the monstrous Cretaceous ammonite, Parapuzosia seppenradensis, which grew to about 3 meters and would probably weigh close to 1500 kilograms!