|A polished Goniatite fossil|
All goniatites had an external shell like other ammonites. It was divided internally into chambers filled with gas, giving it buoyancy. An open chamber at the front of the shell was where the animal lived. It drew in and expelled water through a ventral spout called a siphuncle. They had a head with two well developed eyes, and arms (or tentacles). They were free-swimming.
|Wikispecies has information on: Goniatitida.|