Chesapecten jeffersonius
Extinct scallop, first North American fossil illustrated in scientific literature.
Chesapecten jeffersonius is the preserved remains of an extinct scallop that existed on Virginia’s coastal plain during the early Pliocene, roughly four to five million years ago. It is the official state fossil of Virginia. This species holds the distinction of being the first fossil from North America ever depicted in scientific literature, thanks to a drawing published by Martin Lister in 1687. The fossil is frequently found in cliffs along major rivers in southeastern Virginia and eastern North Carolina, and it serves as the index fossil for the Lower Yorktown Formation. In 1824, geologist John Finch collected a large batch of mollusk fossils, including this scallop, near Yorktown, Virginia, and donated them to the Academy of Natural Sciences of Philadelphia. There, scientist Thomas Say described the species and named it *Pecten jeffersonius* in honor of Thomas Jefferson. To tell it apart from other *Chesapecten* species, look for 9 to 12 ribs and a fairly rounded shell edge.
Quick Facts
- Taxon
- Chesapecten jeffersonius
Facts from the source article.
Lore & Background
In 1687, Martin Lister published a drawing of Chesapecten 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 this species, 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.
Chesapecten jeffersonius is distinguished from other Chesapecten species by the number of ribs (9 to 12) and a rather rounded shell edge. It is 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.
Reader's Guide
Chesapecten jeffersonius holds significance as the state fossil of Virginia and as an index fossil for the Lower Yorktown Formation, aiding in the identification of early Pliocene strata. Its legacy includes being the first North American fossil illustrated in scientific literature, a drawing by Martin Lister in 1687. The species was later described by Thomas Say, who named it Pecten jeffersonius to honor Thomas Jefferson, based on specimens collected by John Finch from Yorktown, Virginia. The fossil is commonly found in Coastal Plain cliffs along major rivers in southeastern Virginia and eastern North Carolina. Its identification relies on a rib count of 9 to 12 and a rounded shell edge, distinguishing it from other Chesapecten species. The species lived between four and five million years ago during the early Pliocene epoch.
Did You Know?
- Chesapecten jeffersonius was the first North American fossil to be illustrated in scientific literature, in a 1687 drawing by Martin Lister.
- It is the state fossil of the Commonwealth of Virginia.
- It was named Pecten jeffersonius by Thomas Say to honor Thomas Jefferson.
Frequently Asked Questions
What is Chesapecten jeffersonius?
It is the preserved remains of an extinct scallop that inhabited Virginia's coastal plain during the early Pliocene, roughly four to five million years ago. Today it holds the title of Virginia's official state fossil.
Where can you actually find Chesapecten jeffersonius fossils?
The fossils are most often exposed in Coastal Plain cliff faces along major rivers in southeastern Virginia and eastern North Carolina, making those riverbank outcrops the go-to spots for spotting them.
Why is Chesapecten jeffersonius a landmark in the history of science?
It was the first fossil from North America ever depicted in a scientific publication, thanks to a drawing Martin Lister published in 1687. That single illustration marked a genuine milestone in the continent's documented natural history.
What role does Chesapecten jeffersonius play in geology?
It serves as the index fossil for the Lower Yorktown Formation, meaning its presence lets geologists identify and correlate that specific rock layer across different regions.
How old is Chesapecten jeffersonius and when did it live?
The species dates to the early Pliocene epoch, placing it between four and five million years old. It lived in the shallow coastal waters of what is now Virginia's coastal plain before going extinct.
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