Ammonites were molluscs that lived between 240 million and 65 million years ago. They came in a range of sizes from only a couple of centimetres to 2 metres in diameter.
Found in the Red Crag deposits at Walton on the Naze.
Megalodons were a species of shark that lived during the Pliocene era (16 to 1.6 million years ago).
They were one of the largest and most powerful marine predators and could reach up to 16m long, with jaws 2m wide.
The teeth of the megalodon could be up to 21cm long. This example is large at about 10cm long, but small examples are still frequently found on the beach at Walton, washed out from the cliffs.