Sliced Large Ammonite Fossil Pair
Measures Roughly 6 1/2' (Each Slice)
 
Ammonites were a diverse group of extinct marine mollusks that first appeared in the fossil record during the Devonian period, about 400 million years ago. They reached their peak diversity and abundance during the Mesozoic era, which spanned from about 252 to 66 million years ago. Ammonites are best known for their spiral shells, which varied greatly in size, shape, and ornamentation.
 
During the Mesozoic era, ammonites evolved into a wide array of forms, from small, simple shells to large, elaborately ornamented ones. They were a dominant group in many marine ecosystems and played an important role as predators and prey. They had a soft body inside the shell and used tentacles to capture food, such as plankton, and a siphon to expel water.
 
One of the most distinctive features of Mesozoic ammonites is their intricate shell ornamentation. The shells of some species were adorned with intricate ridges, knobs, spines, and other structures that likely served a variety of functions, such as protection from predators or buoyancy control. Some ammonite shells also had distinctive color patterns, which may have helped them blend in with their environment or attract mates. Mesozoic ammonites were incredibly diverse, with thousands of species known from around the world, and their fossils are highly valued by scientists and collectors alike.