Trace fossils of the bivalve Panopea faujasi, Pliocene, Rhodes, Greece

The large bivalve, Panopea faujasi Ménard de la Groye, 1807 is locally abundant in shallow marine sandy facies in Late Pliocene sediments of Rhodes, where it occurs in life position within its burrow. Several Panopea‐trace fossils were sectioned in a vertical plane and others in series of horizontal sections, in order to study them in detail. Morphology of the structures produced by different individuals varied greatly, and even neighbors at the same horizon were unalike in detail. All show retrusive, upward shift in accordance with sedimentary accretion, but some also show protrusive movement as a response to erosive phases. As a response to sedimentation, the bivalve dug its way upwards by moving terrigenous grains and skeletal material from above it to below. In cross section the outline is slightly oval to circular. The longest example of these retrusive structures was preserved to a length of 86 cm and had a diameter of about 15 to 20 cm. As the bivalve has a long lifespan, and burrows deeply, the structures have good preservation potential and can reveal details of depositional history. The trace fossil is named Scalichnus phiale igen. et isp. nov.