A nautilus is a name for any one of the 6 known species of cephalopod in the Nautilidae family. They are shelled mollusks in the sea and are the only known remaining members of the family Nautiloidea.
At one point in Earth's history, the nautilus was once a powerful predator, but as the world evolved many other organisms surpassed this creature. Now this species is found only in the Indo-Pacific...