#mesozoic era
- Ammonite — A fossil marine cephalopod mollusk from the Ammonoidea subclass, characterized by an external, planospiral, and chambered calcareous shell, which lived from the Devonian period until the end of the Cretaceous. The fossils of these organisms are widely used in stratigraphical geology as index fossils for the precise dating of sedimentary rock layers from the Mesozoic era.
- Anisian — A geological stage or substage located at the base of the Middle Triassic epoch, chronologically spanning from approximately 247 to 242 million years ago. As an adjective, the term refers to rocks, sediments, or fossils formed during this time interval, internationally defined by the appearance of specific ammonite and conodont assemblages within reference Alpine geological sections.