Ammonites

Ammonite fossils are the remains of ancient marine mollusks called ammonoids, which were abundant in Earth’s oceans for nearly 350 million years. These creatures had spiral-shaped shells with intricate chambers, similar in appearance to a coiled ram’s horn. Ammonites were diverse in size, ranging from less than a centimeter to over two meters in diameter. Their fossils are valuable to paleontologists because they are excellent index fossils, helping to date the rock layers in which they are found. Ammonites are known for their intricate and beautiful shell patterns, which can vary widely between species. Their extinction around 66 million years ago, along with the dinosaurs, marks the end of an era in Earth’s history.