400 million years ago, the amazing Ammonite swam through the seas. These cephalopods survived several mass extinction events, including the Permian–Triassic "Great Dying" which wiped out 96% of all marine species.

Now, we know them by the iconic spiral shells they left behind in the fossil record, each a unique and beautiful treasure from a fascinating creature.

This specimen is one of these pocket-sized fossil shells from a 66,000,000-year-old Ammonite!

The Amazing Ammonite Pocket Fossil is a display box that contains a small, <1 in fossil shell, a folding informational card about the ammonite, authenticity details, and a beautiful illustration of the prehistoric creature!

We wanted to put the most bang for your buck into this specimen. It's an all-in-one package that makes a great gift for kids, students, office parties, or just about anyone who loves learning about extinct creatures and fossils!

The tooth and folding card both fit snugly in the black 1 3/4" x 1 1/8" x 5/8" charm box, so it truly is a Pocket Fossil!

Want to see more ammonites? Check out our super-sized collection below!

Ammonites are an extinct group of cephalopods which entered the fossil record 400 million years ago. They survived several mass extinction events, including the Permian–Triassic "Great Dying" which wiped out 96% of all marine species. They finally succumbed during the Cretaceous-Paleogene extinction event 66 million years ago, which also wiped out the dinosaurs.

The size of ammonite shells range from sub-centimeter dwarf species to giants nearly three meters in diameter. Most iconic shells exhibit a nearly perfect logarithmic spiral.

How these creatures lived is of intense interest to science as ammonites likely played a vital role in the food chain in the ancient seas.  Evidence exists to suggest that ammonites were a prime food source for Mosasaurs and fishes, while other studies suggest the "bite marks" were created after death by limpets or even by other cephalopods.

The Late Cretaceous was a time during which the interior of North America was covered by the Western Interior Seaway which extended from the Arctic Ocean to the Gulf of Mexico. As mountains rose in the west, they were eroded, and rivers draining eastward deposited their sediments into this interior sea some 70 - 75 million years ago. 

Ammonite shells grew in a natural spiral and made a consistent, mathematically significant pattern. This special shape is known as a logarithmic spiral.

The main property of a logarithmic spiral is that the shape of the spiral is unaltered as it increases in size. Each turn is a pure geometrical progression of the last with a common ratio.  This form is found in many natural phenomena, from the shape of galaxies to patterns on sunflower heads.

How these creatures lived is of intense interest to science, as ammonites likely played a vital role in the food chain in the ancient seas. Evidence exists to suggest that ammonites were a prime food source for Mosasaurs and fishes, while other studies suggest the bite marks on their remains were created after death by limpets or even by other cephalopods.

Many thousands of distinct species make up the long-lived ammonoid subclass.  Though most ammonite shells are the classic spiral, there are also straight and gastropod-like shells and even some shells that are partially uncoiled.  The surface of the shells also vary quite widely, from smooth to wildly thorny.

Ammonites were an incredibly diverse and plentiful group of animals that survived for hundreds of millions of years and lived all across the planet. Their rapid diversification and tough, rocky shells means there are many different and easily identifiable species in the fossil record. Because of this, scientists can use them to easily identify the age of other fossils and geologic deposits found in the same layer of the ammonites. They're a welcome sight to the eyes of any inquisitive geologist!

Aside from their complex shells, there is little direct evidence regarding the appearance of ammonites due to the absence of soft tissue fossils. However, many scientists believe ammonites had bodies similar to that of the present-day Nautilus.

The shells of Cleoniceras are separated into chambers called septa, which show highly complex sutured patterning. These beautiful patterns evolved over time to solve a difficult problem: shell strength. In order to survive at deeper pressures, ammonites needed tougher shells, but increasing the size and thickness of the shell could slow them down.

Sutured shells could spread the water pressure across the surface, increasing the strength of each chamber without making it much heavier. This made the shells safer at high depths while staying efficient to grow and kept the animal swimming quickly.