'' Chesapecten jeffersonius '' is the

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

ized form of an extinct

scallop Scallop () is a common name that encompasses various species of marine bivalve mollusks in the taxonomic family Pectinidae, the scallops. However, the common name "scallop" is also sometimes applied to species in other closely related families ...

, which lived in the early Pliocene epoch between four and five

million One million (1,000,000), or one thousand thousand, is the natural number following 999,999 and preceding 1,000,001. The word is derived from the early Italian ''millione'' (''milione'' in modern Italian), from ''mille'', "thousand", plus the au ...

years ago on Virginia's coastal plain. Chesapecten jeffersonius are commonly found in strata exposed along Coastal Plain cliffs along major rivers in southeastern Virginia and eastern North Carolina, and it is the index fossil for the Lower Yorktown Formation. It is the

state fossil Most American states have made a state fossil designation, in many cases during the 1980s. It is common to designate one species in which fossilization has occurred, rather than a single specimen, or a category of fossils not limited to a single ...

of the Commonwealth of Virginia in the United States.

Paleontological history

In 1687, Martin Lister published a drawing of ''C. jeffersonius'', making it the first North American fossil to be illustrated in scientific literature. In 1824, geologist John Finch gathered a large collection of mollusk fossils, including ''Chesapecten jeffersonius'', from the vicinity of Yorktown, Virginia, and gave them to scientists at the Academy of Natural Sciences of Philadelphia (ANSP). Scientist Thomas Say, at ANSP, described the species and named it ''Pecten jeffersonius'' to honor Thomas Jefferson.

Identification

''Chesapecten jeffersonius'' is distinguished from other ''Chesapecten'' species by the number of ribs (9 to 12), and a rather rounded shell edge.

References

Virginia: ''Chesapecten jeffersonius'' (state fossil)
Pectinidae Neogene bivalves Pliocene animals of North America Symbols of Virginia Taxa named by Thomas Say Prehistoric bivalves Bivalves described in 1824 {{paleo-bivalve-stub