Wikipedia
Aviculopecten
Aviculopecten is an extinct genus of bivalve mollusc that lived from the Early Devonian to the Late Triassic in Asia, Australia, Europe, North America, and South America.
A fine fossil of the species Aviculopecten subcardiformis has been found in the 345 million year old Logan Formation of Wooster, Ohio. It is an external mould and the impression left by the valve is so clear that the fine ridges and even the growth lines are visible.