This listing is for ONE (1) Ammonite Fossil Pair - You Choose. You will get both halves. Fossilized ammonite that has hollow chambers and druzy, formed during the Triassic Period! These specimens were found in Timor, Indonesia. Ammonites are prehistoric sea creatures that belong to a group know as the cephalopods. During the Jurassic and Cretaceous period, 65-240 million years ago, they were one of the most abundant animals in the ocean. They are ancestors of the nautilus. Ammonite shells are wonderful fossils to display in any space as they exhibit the golden ratio in a Fibonacci spiral. Why You'll Love It: * A Piece of Ancient History: This fossil is amazingly well-preserved, a great record of the ancient seas from millions of years in the past.