Orthoceraswere conical-shelled creatures who became flat while swimming and used its tentacles to hunt. The conical shell, known as an “orthocone”, were composed of many bumpy chambers with little space between them.
Ammonites, on the other hand, had spiral shells. They were the most numerous marine species on Earth during the Mesozoic, appearing in the Devonian and going extinct, along with animals such as dinosaurs or Belemnitida, in the K-Pg extinction event. They are closely related to modern species such as octopuses or squid, and according to residue found in fossils, they also release ink as an escape mechanism, in the same manner as squid.
Taxonomically speaking, both Orthocerasand Ammonites are of the Cephalopoda class, but they independently split into two subclasses: Orthoceratoidea and Ammonoidea respectively. This Moroccan fossil you see before you have both types criss-crossing across a fossil layer. How interesting!
You will note the difference between the fossils that have been cleaned and polished and those that have not among the collection. Try to identify Orthoceras and Ammonites in the