Ecphora

Ecphora gardnerae is a marine gastropod from the Miocene epoch. Its four raised spiral ribs set it apart from most other fossil snails and make specimens easy to identify even when worn or broken. The species was named for Julia A. Gardner, a USGS paleontologist whose studies of Atlantic coast Miocene mollusks became the standard reference for the field.

Ecphora gardnerae was a small, heavy-shelled predatory snail with a shell typically 2 to 3 inches (5 to 7 cm) long. Shells are often tinged reddish-brown from iron absorbed during fossilization, giving polished specimens a warm amber color. The shell's thick calcite walls made it unusually resistant to crushing, which is one reason so many complete specimens survive in the Calvert Cliffs shale.

Like modern whelks, the Ecphora drilled through the shells of clams and oysters to feed on the soft tissue inside. It lived in shallow marine waters during the Miocene and went extinct around 3.5 million years ago as coastal conditions along the Atlantic shifted at the close of the epoch.

Maryland designated the Ecphora as its state fossil in 1984. The Calvert Cliffs had been a well-known fossil locality since the early 1800s, and the Ecphora was already one of the most frequently collected shells from the Chesapeake Bay shoreline, familiar to naturalists, collectors, and schoolchildren alike by the time the designation was made.

The species carried the name Ecphora quadricostata throughout most of the 20th century. In 1994, paleontologist Emily J. Vokes revised the taxonomy of the group and renamed the Maryland form Ecphora gardnerae, after Julia A. Gardner (1882-1960), a pioneering USGS geologist who produced the definitive survey of Atlantic coast Miocene mollusks.

The Calvert Cliffs, a 24-mile row of Miocene bluffs along the western shore of the Chesapeake Bay in Calvert County, are the main source of Ecphora fossils in Maryland. As the cliffs erode, shells drop onto the beach and can be picked up without digging. Calvert Cliffs State Park and Flag Ponds Nature Park both offer beach access where visitors regularly find Ecphora specimens.

The Calvert Marine Museum in Solomons holds one of the country's best collections of Calvert Cliffs fossils, including many Ecphora shells, and has exhibits explaining the Miocene sea environment that produced them.