Tubular burrows of marine bivalve mollusca (Pholadidae). They use a teethy shell to grind away at rock to create tubular burrows. The type area is a Naturdenkmal in the village Heldenfingen, (Gerstetten, Eastern Alb). It denominates the rocky cliff of the Lower Miocene sea („Upper Marine Molasse]]“ of the Molasse basin), which is documented across the Swabian Alb from west to east. The Pholad borings, measure 0,5-2 cm at the top of the rock and 3 cm at the bottom. The borings obviously represent several generations.