Astarte incerta (Wood, 1853)

This compressed, oval-shaped burrower represents the quieter, more sheltered niches of the ancient North Sea. Because its shell is moderately thin and decorated with fine, regular concentric lines, it was not built to withstand the punishing forces of high-energy sandbanks. Instead, it preferred calmer, muddy-sand environments, making it an excellent ecological indicator for peaceful depositional phases between major storm events.