Faune du calcaire carbonifère de la Belgique Bruxelles, F. Hayez, impr, 1878-87, Belgium, brachiopod, fossil, carboniferous, fishes, fossil, mollusks, fossil, paleontology, fossils, sea, ocean, shells, This illustration features a collection of detailed representations of various ammonite fossils. Displayed are six distinct specimens, showcasing their intricate shell structures and spiraled forms. Each fossil is labeled with a number, indicating their classification, and accompanied by smaller images of individual spiral shapes and cross-sections. The illustration serves as a scientific study of these ancient marine cephalopods, highlighting the unique features and varying sizes of the shells. This depiction emphasizes the complexity and diversity of ammonites, which thrived during the Mesozoic era.