The goniatite group includes the majority of Palaeozoic ammonites and most of the guide fossils of this age used to identify rock formations.
Ammonites are a group of cephalopod animals that lived as swimmers in the deeper parts of the ancient oceans. In appearance their shells were coiled and smooth. Goniatites are noted for their angular zigzags in their sutures, and the siphuncle on the outside of the whorl.
They have been called “angel stones” because of their growth suture patterns. The goniatite ammonite became extinct by the end of the Permian time.