Ammonites were shelled cephalopods that died out about 66 million years ago. Fossils of them are found all around the world, sometimes in very large concentrations. The often tightly wound shells of ...

How can the soft bodies of coleoid cephalopods so aptly hide in their environment? Why must they? What cells and specialized organs make such crypsis possible for one of the older evolutionary ...

The chambered, or pearly, nautilus (Nautilus pompilius) is a charismatic cephalopod species known for its exceptional spiraling, chambered shell. It belongs to a family that has barely changed since ...

The many chambers of their shells likely helped these cephalopods glide through the planet’s warm, shallow seas. A thin, tubelike structure called a siphuncle pumped air through the interior ...