The largest and one of the most well preserved fossil specimens of an ammonite has been discovered on Seymour Island off Antarctica. Belonging to the class Molluscs, these animals have soft bodies like snails encased in calcareous shells (Discovery Vol 16, No 9).
Called Diplomoceras ntsudmum, this animal belonged to the uncoiled form of ammonites. Discovered by Purdue University's (US) William Zinzineister, it measures more than 12 It in length when straightened out. The Purdue team plans to submerge a model of the shell to observe the flow of water through it.