Ammonites: Extinct Cephalopods of the Mesozoic Era

Ammonites are extinct species of cephalopods, which lived during the Mesozoic era, from 240 to 65 million years ago. They were related to modern squid, octopus and cuttlefish.
The name "ammonite" comes from the shape of their fossilized shells, which resembled ram's horns. Ammonites were a very successful group of animals, with over 100 species known.
Ammonites were marine animals that lived in warm seas, and their fossils have been found all over the world. They were likely bottom-dwellers, feeding on small fish and other invertebrates.
Their shells were made of chitin, a tough, flexible material that is also found in the shells of modern crustaceans. The shells had a spiral shape, with the largest species reaching up to 2 meters in length.
Ammonites are important fossils for paleontologists because they provide valuable information about the Earth's history. They can be used to date rocks and reconstruct ancient ecosystems.
The extinction of the ammonites is believed to have been caused by a combination of factors, including changes in ocean currents, volcanic eruptions, and the evolution of new species that outcompeted them for resources.