Ammonites, Trilobites
Ammonites went extinct long back as marine animals of the subclass Ammonoidea in the class Cephalopoda, phylum Mollusca. Trilobites as arthropods from the class Trilobita went extinct during the Late Devonian extinction. Today they present us the most common fossils belonging respectively to the Cretaceous period and the Late Devonian period of geology.
