Goniatites are a member of the Marine Invertebrate family, they are also closely related to the octopus and squid.
The shell initially was divided into chambers where the animal would live in the largest chamber and fill the other chambers with gas. Thus making the animal more buoyant in water.
One special feature of the Goniatite is its characteristic zigzag's on the shell.
Width - Approx. 5 to 8cm