English: Fossil finds at Walton on the Naze These fossils were washed from the crumbling Red Crag, and are from the end of the Pliocene period, about three million years ago. Except for the small sharks teeth which come from the underlying London Clay, and are very much older. The star of the show is the famous "Left Handed" Whelk (Neptunea contraria angulata). They differ from all present day gastropods, (the light coloured one,) in that their shells spiral the opposite way. One suggestion as to the reason why, is that they evolved to defeat a particular crab that had developed a special claw, with which it could expertly extract the creature from its shell. The two halves of the bivalve Dog Cockle (Glycymeris glycymeris) are also shown.