Bivalve oyster shell
Devil’s Toe Nail
This is a ‘classic’ bivalve shell from the Blue Lias around Lyme Regis. This is not, as folklore might have it, the gnarled toe nail from some long lost monster! It is a humble and common oyster that sat on the sea bed with the larger heavier shell acting as an anchor. It filtered sea water for food. Look carefully and you’ll see occasional growth rings that are slightly stronger than the others – these may in fact be annual growth lines. They suggest that these animals were about five to six years in age when they died.
Find out more about bivalves on the molluscs pages.