Ammonite (Fossil)

About the Ammonite (Fossil)

Extinct relatives of nautilus that dominated the oceans for 300+ million years before dying out with the dinosaurs 66 million years ago. Over 10,000 species are known from fossils. Their shells displayed an incredible variety of shapes and sizes. They are among the most common fossils found. Their rapid evolution makes them excellent index fossils for dating rock layers. Some reached 2 meters in diameter. Their extinction allowed nautiluses to survive as the last living shelled cephalopods. They are found on every continent including Antarctica.