The Nautilus (in Greek 'sailor') has survived relatively unchanged for 6000 years and is one of the only shells to survive from the Dinosaurs era. This is why the Nautilus is sometimes referred to as a "living fossil". The Nautilus is a nocturnal creature and spends most of its time in the great depths of the ocean. The Nautilus shell, lined with mother-of-pearl, grows into increasingly larger chambers throughout its life and so has become a symbol for expansion and renewal. The Nautilus swims about the ocean bottom in search of shrimp or other prey. It uses up to 94 small, suckerless contracting tentacles for capturing them. Nautilus is the last surviving genus of the ancient order Nautiloidea, important in paleontology for dating the strata in which it appears.