Ammonites. Sectioned fossilised ammonites (Astero- ceras smithi). Ammonites were marine molluscs which resembled the modern nautilus. Their chambered

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Ammonites. Sectioned fossilised ammonites (Astero- ceras smithi). Ammonites were marine molluscs which resembled the modern nautilus. Their chambered shell contained air to help regulate their buoyancy. They were abundant in coastal seas from 380 million years ago (mya) in the Devonian period to the mass extinction at the end of the Cretaceous period 65 mya. These ammonites are from the Jurassic period (208-144 mya).

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Keywords: ammonites, animal, animals, asteroceras, extinct, fossil, fossilised, fossils, invertebrate, invertebrates, jurassic, marine, mollusc, nature, palaeontology, paleontology, period, sectioned, smithi, spiral