The ammonoid collection comprises around 5,000 pieces, making it one of the largest in Europe. Ammonoids are a group of shell-bearing squids that populated the world's oceans from the Devonian to the Cretaceous at the same time when dinosaurs dominated the mainland. The ammonoids quickly developed new, sometimes fantastic-looking housing types. They are therefore just as important for evolutionary biology as they are for biostratigraphy, i.e. the temporal classification of sediments with the help of fossils.