Ammonites are an extinct group of mollusk animals that are closely related to octopuses and squid. The earliest traces of Ammonite date back to 420 million years ago, while the last known traces fall to 60 million years ago. Its name is derived from the Egyptian god Ammon, who was depicted wearing a ram's horn. Pliny the Elder first recorded these fossils in 79 A.D. near Pompeii and originally named them Ammonis Cornua after their horn-like shape. The creatures that lived in these shells swam in open waters, filling chambers of the shell with gas to maintain buoyancy. Ammonites are found all over the world, however, a large majority of the commercial supply comes out of Morocco.