27 Şubat 2013 Çarşamba

Maryland State Fossil

Maryland State Fossil

Sea Snail (common name)
Ecphora gardnerae gardnerae 
(scientific name)
Ecphora gardnerae gardnerae is an extinct marine rock snail that lived approximately 5 to 15 million years ago during the Miocene epoch of the Neogene period. This gastropod inhabited the tidal waters of what is now the East Coast of the United States. This genus of fossils is significant because it was one of the first fossils of the New World to be illustrated in a European scientific work.Ecphora appeared in the third edition of Martin Lister’s Historiae Conchyliorum (History of Conchs), published in England in 1770.
This fossil snail was designated the official state fossil by the state of Maryland in 1984, but in March 1994, there was a name change. The snail was originally called Ecphora quadricostata, but this was changed when the paleontology community realized Maryland’s fossil snail was a separate species from Ecphora quadricostata. Ecphora quadricostata did not actually occur in Maryland, but rather along the East Coast from Virginia to Florida. As of October 1, 1994, Maryland’s official state fossil is called Ecphora gardnerae gardnerae. This fossil, as well as other species of Ecphora, is commonly found in the St. Mary’s Formation on the Eastern Shore of Maryland and Virginia, along the Chesapeake Bay, and in parts of southern Maryland.
Maryland’s Calvert Cliffs State Park and a community known as Scientists Cliffs, on the western side of the Chesapeake Bay, are considered the best marine Miocene deposits in the world and particularly good places to search for the state fossil. During the Miocene epoch, a warm, shallow sea covered present-day southern Maryland. Today, this area is home to over 600 species of fossils, including plants, mammals, birds, insects, fish, other mollusks, and shark’s teeth. Scientists have studied the beaches and cliffs in this area since colonial times. Breezy Point and Flag Ponds Nature Park on the Chesapeake Bay are also well-known fossil deposit sites. In addition to an official state fossil, Maryland has also designated an official state dinosaur, the astrodon (Astrodon johnstoni).
The genus name for this fossil, Ecphora, comes from a Greek word meaning "protruding." The species name for this fossil honors the work of late U.S. Geological Survey paleontologist  Julia Gardner.Ecphora gardnerae gardnerae was scientifically named in 1987.
The shell of this fossil is normally brown in color, as opposed to white like most mollusks. This snail’s shell is distinguished by four protruding ribs, or costae, that are T-shaped in cross-section. The hollow at the end of the coil, called the umbilicus, is relatively wide on this snail.
Like all members of the family Muricidae, these rock snails were predatory carnivores. They fed on other mollusks by boring holes into the shells of their prey with a toothed appendage called a radula. Most mollusks, except for bivalves, possess radulas, which they use to scrape or break up food.
The genus Ecphora first appeared in the Oligocene epoch and became extinct at the end of the Pliocene, approximately two million years ago. Because of evolutionary changes over time, species ofEcphora can be used by paleontologists and geologists to date sedimentary rock layers. It is believed that gradual global climate change led to the extinction of the genus.
The fossil illustrated in Historiae Conchyliorum was found in St. Mary’s County, Maryland, in 1685.

Click to enlarge an image
State Prehistoric Creature
Illustration of the Predatory Sea Snail

Species:E. gardnerae
Author: World Trade Press

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