Ammonites were creatures with flat shells that had a regular, helically-spiraled shape, that existed on Earth in prehistoric times, having evolved from nautiluses. Discoveries have shown that they ranged in size from a few centimeters to as big as about 1.7 meters in diameter. Ammonites are not related to shellfish; they were soft-bodied mollusks just like squid and octopuses. As they are now extinct, we can only learn about them from fossils. They were generated on the Earth from the end of the Paleozoic era's Silurian period (around 420 million years ago) to the middle of the Devonian period (around 380 million years ago). They inhabited the oceans around the world until the Cretaceous period of the Mesozoic era (around 65million years ago), meaning the species existed for a total of around 350 million years-CanonAmmonite Fossil Papercraft
