Ammonites

Spiral-shaped beauties

Ammonites were shellfish that lived in all seas and oceans. There were many hundreds of different species, with a great variety of shapes and ways of life. But all species had one thing in common: a spiral-shaped shell, the interior of which was divided into several chambers.

The ammonite itself occupied only the outermost chamber. The other chambers could be filled either with water to facilitate sinking or with air to aid buoyancy. By regulating the balance between water and air, the animal could keep itself suspended in the water.

Due to this way of life, ammonites were severely restricted and were driven through the sea by the currents. They fed on small crustaceans, fish, and food particles. But despite, or perhaps because, of their primitive way of life, ammonites managed to exist on Earth for more than 335 million years.

At the end of the Cretaceous period, they became extinct, just like the dinosaurs. And since fossilised ammonites are often found, like trilobites, they are often used by geologists as a kind of palaeontological measuring device to determine the age of rock strata.

In the Middle Ages, it was believed that the spiral-shaped ammonites were snakes that God had turned into stone as a form of punishment. And so, today, fossils of ammonites can be found again and again, into which zealous stonemasons of the Middle Ages carved snake heads.