Ammonites were shelled cephalopods (squid, octopus, cuttlefish etc) that died out about 66 million years ago and first appeared about 450 million years ago. Fossils of them are found all around the world, sometimes in very large concentrations. The shells of ammonites look like coiled snakes. At the end of the Cretaceous Period, 65 million years ago, an asteroid colliding with Earth brought on a global mass extinction.
Ammonites evolved rapidly. It is estimated there were over 10,000 species of ammonaite and they varied in size from a few millimeters to 1.8 meters in diameter. Ammonites can be a useful tool for scientists. Because they are so common and evolved so rapidly, they are excellent to help determine the age of the rocks in which they are fossilised.
This specemin is therefore at least 66 million years old, but likely 100’s of millions of years old.
Thanks to the UK Geology Project for providing the fossils
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