Nautiloids, like Ammonites, are part of the cephalopod family. However, unlike Ammonites, Nautiloids still survive today. The animal, Nautilus, lives in a coiled shell, such as this fine example, only exposing its head and tentacles. The chambers within the shell, marked by curved lines on the shell’s exterior, would be filled with gas, allowing the animal to live in different depths of the ocean.
Nautiloids first appeared 500 million years ago, during the Paleozoic era, and were the main predatory species. Only a few species survive today and inhabit seas around Australia and the Philippines. They are sometimes referred to as “living fossils”, due to the belief that the remaining species are of a similar form to their ancestors.