Chesapecten jeffersonius (Pliocene scallop) fossil shell; public domain photo on Wikipedia.
Official State Fossil of Virginia
Virginia designated Chesapecten jeffersonius as the official state fossil in 1993. All State Fossils
Chesapecten jeffersonius lived in the shallow seas along the Mid-Atlantic during the Miocene to Pliocene epochs (approximately 8 to 3 million years ago). The fossils of this long-extinct scallop are commonly found in exposed strata along Coastal Plain cliffs of major rivers in southeastern Virginia.
Source
