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'Jefferson's Chesapeake Scallop' Yorktown Formation, Sunken Meadow Member
This distinctive scallop is the state fossil of Virginia, and is the first fossil described in North America, in 1687. It is commonly found in stream valleys and on river beaches of Southeast Virginia and Eastern North Carolina. This species is the index fossil for the Lower Yorktown Formation. This species is usually distinguished by the number of ribs (9 to 12) and the rather rounded shell edge. Immature scallops attach themselves to the sea floor, whereas adult individuals are free-swimming. Chesapecten is a lineage of scallops that flourished in the Chesapeake Bay area from Eastover to Yorktown time (about 8 to 3 million years ago). Species dominated during different intervals of time: C. middlesexensis during the Miocene (Eastover Formation); C. jeffersonius during Early Pliocene (Lower Yorktown Formation, about 4.5 to 4.3 million years ago); and C. madisonius during Late Pliocene time (Upper Yorktown Formation, about 4 to 3 million years ago). Other scallops lived at the sametime, but these were the most abundant. |
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| © 2006 W&M Department of Geology
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