''Ostrea compressirostra'' is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

of prehistoric saltwater

oyster Oyster is the common name for a number of different families of salt-water bivalve molluscs that live in marine or brackish habitats. In some species, the valves are highly calcified, and many are somewhat irregular in shape. Many, but no ...

, a fossil that is found in the

Yorktown Formation The Yorktown Formation is a mapped bedrock unit in the Coastal Plain of Maryland, Virginia, North Carolina and South Carolina. It is overconsolidated and highly fossiliferous. Description The Yorktown is composed largely of overconsolidated san ...

Chowan River Formation The Chowan River Formation is a geologic formation in North Carolina. It preserves fossils dating back to the Neogene period Period may refer to: Common uses * Period (punctuation) * Era, a length or span of time *Menstruation, commonly refer ...

, Waccamaw Formation, and their equivalents in

Virginia Virginia, officially the Commonwealth of Virginia, is a U.S. state, state in the Southeastern United States, Southeastern and Mid-Atlantic (United States), Mid-Atlantic regions of the United States between the East Coast of the United States ...

North Carolina North Carolina ( ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It is bordered by Virginia to the north, the Atlantic Ocean to the east, South Carolina to the south, Georgia (U.S. stat ...

South Carolina South Carolina ( ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders North Carolina to the north and northeast, the Atlantic Ocean to the southeast, and Georgia (U.S. state), Georg ...

, and

Georgia (U.S. State) Georgia is a U.S. state, state in the Southeastern United States. It borders Tennessee and North Carolina to the north, South Carolina and the Atlantic Ocean to the east, Florida to the south, and Alabama to the west. Of the List of states a ...

.Paleobiology Database: Ostrea compressirostra
/ref> Its maximum size is roughly in length.

References

Ostrea Bivalves described in 1824 {{Ostreidae-stub