nautilus

Sea animal related to octopuses and squids, with many short, grasping tentacles surrounding a sharp beak, but different in that it has an outer shell. It is a cephalopod, a type of mollusc, and is found in the Indian and Pacific oceans. The well-known pearly nautilus (N. pompilius) has a chambered spiral shell about 20 cm/8 in in diameter. Its body occupies the outer chamber. (Genus Nautilus, class Cephalopoda.)

Nautiluses detect their prey by smell, using rhinopores, paired openings just below the eyes, according to US researchers in April 2000. Paper nautilus is another name for the argonaut, a type of octopus.

The living nautiluses are representatives of a group common 450 million years ago.

Nautilus

The name of the world's first nuclear-powered submarine, launched by the USA in 1954; it sailed under the icecap to the North Pole.