A living fossil


Kingdom: Animalia

Phylum: Mollusca

Class: Cephalopoda

Subclass: Nautiloidea

Order: Nautilida

Superfamily: Nautilaceae

Family: Nautilidae

Genus: Nautilus

Species: Nautilus Repertus

Nautilus has a family.

The closest relative to a nautilus is an octopus. Both the nautilus and the octopus move in the same way. They use their water propulsion to push themselves in the direction they want to move. Both move backwards as the water exits by their heads.

Where are they found?

They are usually found in the Indo-Pacific ocean in-between 100 m to 300 m down. It is cold that far down so they usually stay in packs to conserve heat. They come up to 30m at night to feed.

Nautilus is a player!

A nautilus has a different mating partner ever year. since they move in packs, they usually mate with one of the females in the group, but the males greatly outnumber the females in all recorded data. This means that it is a contest to get the female, but since female nautili only choose one male, some nautili are not going to reproduce.

How big are they?

They can range from 6.29921 inches (the Bellybutton Nautilus) to 10.55118 inches (Nautilus Repertus). Nautilus pompilius, the most common nautilus, weighs 28.9829 ounces.

Aren't there nautilus fossils, so why aren't they all dead?

The nautilus is in a small group of animals and plants that haven't evolved much from their prehistoric ancestors. They are called "living fossils". Along with the nautilus, this group includes turtles, horse-shoe crabs, and ferns.

Hold up, I see a predator!

The nautilus's predators are octopus, sharks, triggerfish, and turtles. These can penetrate the nautilus's shell. When the nautilus sees or senses one of these predators, it retreats into its strong shell.


The nautilus, a mollusk thought by sailors to be a kraken, is among the group of animals called "living fossils". There are fossils of these previously thought extinct animals in many museums around the world.

The nautilus was first illustrated in a book called Historiae animalism or "Histories of the Animals" by Conrad Gesner. This book was published in 1551-58 and 1587. Conrad Gesner heard stories from sailors about this creature and decided, based on their descriptions, to draw it.

The nautilus showed up in another book, this time a well-known book, called Twenty Thousand Leagues Under the Sea by Jules Verne. Instead of being a sea monster, it was the name of Captain Nemo's ship. By this time archeologists had found nautili fossils, but still not a living one. Jules Verne had heard about the nautilus myth and about the fossils, giving him the idea to name the ship after the animal.

The first time that a nautilus was found in nature, not as a fossil, was in 1829. A ship near a Polynesian island found it. It was mistaken for a dead cat, but the ship's surgeon decided to take the dead nautilus and preserve it. Two years later the nautilus was declared as a living fossil.