Ammonites lived during the periods of Earth history known as the Jurassic and Cretaceous. Together, these represent a time interval of about 140 million years.
The Jurassic Period began about 201 million years ago, and the Cretaceous ended about 66 million years ago. The ammonites became extinct at the end of the Cretaceous Period, at roughly the same time as the dinosaurs disappeared.
Ammonites were marine animals belonging to the phylum Mollusca and the class Cephalopoda. They had a coiled external shell similar to that of the modern nautilus.
These fossils originate from Madagascar, believed to be species perisphinctes virguloides, from the Jurassic Period. The white exterior is believed to be original, though there are areas of imperfections across all the specimens.
NOTE: The item photographed is similar to the one you will receive. These fossil ammonites are approximately 1.5" in diameter, and weigh between 0.8 and 1.0 ounces.