|
Chesapecten
''Chesapecten'' is an extinct genus of scallop known from marine strata from the early Miocene to the early Pleistocene of the Eastern United States. It flourished in the shallow seas along the Mid-Atlantic during this period. Other scallops lived at the same time, but Chesapectens were the most abundant. Physical Description Like some other large scallops, the shells of ''Chesapecten'' are characterized by a pattern of wide ribs which radiate outward from the apex of the shell. A distinctive feature of ''Chesapecten'' is that the radial ribs on its shell are crossed by much smaller, rough, concentric ribs, which follow the contours of the edges of the shell (are "conmarginal"). The left valve of ''Chesapecten'' is more convex than the right valve. The adductor muscle scar is large and rounded. Distribution The geographical distribution of ''Chesapecten'' is limited to the Atlantic coastal plain of North America, where it can be found as far south as Florida, and as far ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chesapecten Jeffersonius Fossil, Tellus Science Museum
''Chesapecten'' is an extinct genus of scallop known from marine strata from the early Miocene to the early Pleistocene of the Eastern United States. It flourished in the shallow seas along the Mid-Atlantic during this period. Other scallops lived at the same time, but Chesapectens were the most abundant. Physical Description Like some other large scallops, the shells of ''Chesapecten'' are characterized by a pattern of wide ribs which radiate outward from the apex of the shell. A distinctive feature of ''Chesapecten'' is that the radial ribs on its shell are crossed by much smaller, rough, concentric ribs, which follow the contours of the edges of the shell (are "conmarginal"). The left valve of ''Chesapecten'' is more convex than the right valve. The adductor muscle scar is large and rounded. Distribution The geographical distribution of ''Chesapecten'' is limited to the Atlantic coastal plain of North America, where it can be found as far south as Florida, and as far ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chesapecten Barnacles Pliocene VA
''Chesapecten'' is an extinct genus of scallop known from marine strata from the early Miocene to the early Pleistocene of the Eastern United States. It flourished in the shallow seas along the Mid-Atlantic during this period. Other scallops lived at the same time, but Chesapectens were the most abundant. Physical Description Like some other large scallops, the shells of ''Chesapecten'' are characterized by a pattern of wide ribs which radiate outward from the apex of the shell. A distinctive feature of ''Chesapecten'' is that the radial ribs on its shell are crossed by much smaller, rough, concentric ribs, which follow the contours of the edges of the shell (are "conmarginal"). The left valve of ''Chesapecten'' is more convex than the right valve. The adductor muscle scar is large and rounded. Distribution The geographical distribution of ''Chesapecten'' is limited to the Atlantic coastal plain of North America, where it can be found as far south as Florida, and as far ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chesapecten Jeffersonius
'' Chesapecten jeffersonius '' is the fossilized form of an extinct scallop, which lived in the early Pliocene epoch between four and five million years ago on Virginia's coastal plain. Chesapecten jeffersonius are 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. It is the state fossil of the Commonwealth of Virginia in the United States. Paleontological history In 1687, Martin Lister published a drawing of ''C. 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 ''Chesapecten jeffersonius'', from the vicinity of Yorktown, Virginia, and gave them to scientists at the Academy of Natural Sciences of Philadelphia The Academy of Natural Sciences of Drexel University, formerly the Academy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 sand and clay with abundant calcareous shells, primarily bivalves. Stratigraphy The Yorktown unconformably overlies the Miocene Eastover Formation, and conformably underlies the Pliocene Croatan Formation. The Yorktown was divided into members by Ward and Blackwelder (1980). These are in ascending order: Sunken Meadow Member, Rushmere Member, Morgarts Beach Member, and Moore House Member. The uppermost Tunnels Mill Member is recognized in Maryland only. Notable exposures *Type Section: Yorktown, Virginia on southwest side of York River, York County *Carters Grove Bluffs, north side of James River *Moore House Bluff, southwest side of York River, York County (very close to type section) Age Hazel (1971) revised the age of the Yor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Virginia
Virginia, officially the Commonwealth of Virginia, is a state in the Mid-Atlantic and Southeastern regions of the United States, between the Atlantic Coast and the Appalachian Mountains. The geography and climate of the Commonwealth are shaped by the Blue Ridge Mountains and the Chesapeake Bay, which provide habitat for much of its flora and fauna. The capital of the Commonwealth is Richmond; Virginia Beach is the most-populous city, and Fairfax County is the most-populous political subdivision. The Commonwealth's population was over 8.65million, with 36% of them living in the Baltimore–Washington metropolitan area. The area's history begins with several indigenous groups, including the Powhatan. In 1607, the London Company established the Colony of Virginia as the first permanent English colony in the New World. Virginia's state nickname, the Old Dominion, is a reference to this status. Slave labor and land acquired from displaced native tribes fueled the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scallop
Scallop () is a common name that encompasses various species of marine bivalve mollusks in the taxonomic family Pectinidae, the scallops. However, the common name "scallop" is also sometimes applied to species in other closely related families within the superfamily Pectinoidea, which also includes the thorny oysters. Scallops are a cosmopolitan family of bivalves found in all of the world's oceans, although never in fresh water. They are one of the very few groups of bivalves to be primarily "free-living", with many species capable of rapidly swimming short distances and even migrating some distance across the ocean floor. A small minority of scallop species live cemented to rocky substrates as adults, while others attach themselves to stationary or rooted objects such as seagrass at some point in their lives by means of a filament they secrete called a byssal thread. The majority of species, however, live recumbent on sandy substrates, and when they sense the presence of a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pectinidae
Scallop () is a common name that encompasses various species of marine bivalve mollusks in the taxonomic family Pectinidae, the scallops. However, the common name "scallop" is also sometimes applied to species in other closely related families within the superfamily Pectinoidea, which also includes the thorny oysters. Scallops are a cosmopolitan family of bivalves found in all of the world's oceans, although never in fresh water. They are one of the very few groups of bivalves to be primarily "free-living", with many species capable of rapidly swimming short distances and even migrating some distance across the ocean floor. A small minority of scallop species live cemented to rocky substrates as adults, while others attach themselves to stationary or rooted objects such as seagrass at some point in their lives by means of a filament they secrete called a byssal thread. The majority of species, however, live recumbent on sandy substrates, and when they sense the presence of a pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Miocene
The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recent" because it has 18% fewer modern marine invertebrates than the Pliocene has. The Miocene is preceded by the Oligocene and is followed by the Pliocene. As Earth went from the Oligocene through the Miocene and into the Pliocene, the climate slowly cooled towards a series of ice ages. The Miocene boundaries are not marked by a single distinct global event but consist rather of regionally defined boundaries between the warmer Oligocene and the cooler Pliocene Epoch. During the Early Miocene, the Arabian Peninsula collided with Eurasia, severing the connection between the Mediterranean and Indian Ocean, and allowing a faunal interchange to occur between Eurasia and Africa, including the dispersal of proboscideans into Eurasia. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chesapeake Bay
The Chesapeake Bay ( ) is the largest estuary in the United States. The Bay is located in the Mid-Atlantic region and is primarily separated from the Atlantic Ocean by the Delmarva Peninsula (including the parts: the Eastern Shore of Maryland / Eastern Shore of Virginia and the state of Delaware) with its mouth of the Bay at the south end located between Cape Henry and Cape Charles. With its northern portion in Maryland and the southern part in Virginia, the Chesapeake Bay is a very important feature for the ecology and economy of those two states, as well as others surrounding within its watershed. More than 150 major rivers and streams flow into the Bay's drainage basin, which covers parts of six states (New York, Pennsylvania, Delaware, Maryland, Virginia and West Virginia) and all of District of Columbia. The Bay is approximately long from its northern headwaters in the Susquehanna River to its outlet in the Atlantic Ocean. It is wide at its narrowest (between Kent C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Family (biology)
Family ( la, familia, plural ') is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between order and genus. A family may be divided into subfamilies, which are intermediate ranks between the ranks of family and genus. The official family names are Latin in origin; however, popular names are often used: for example, walnut trees and hickory trees belong to the family Juglandaceae, but that family is commonly referred to as the "walnut family". What belongs to a family—or if a described family should be recognized at all—are proposed and determined by practicing taxonomists. There are no hard rules for describing or recognizing a family, but in plants, they can be characterized on the basis of both vegetative and reproductive features of plant species. Taxonomists often take different positions about descriptions, and there may be no broad consensus across the scientific community for some time. The publishing of new data and opin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beach
A beach is a landform alongside a body of water which consists of loose particles. The particles composing a beach are typically made from rock, such as sand, gravel, shingle, pebbles, etc., or biological sources, such as mollusc shells or coralline algae. Sediments settle in different densities and structures, depending on the local wave action and weather, creating different textures, colors and gradients or layers of material. Though some beaches form on inland freshwater locations such as lakes and rivers, most beaches are in coastal areas where wave or current action deposits and reworks sediments. Erosion and changing of beach geologies happens through natural processes, like wave action and extreme weather events. Where wind conditions are correct, beaches can be backed by coastal dunes which offer protection and regeneration for the beach. However, these natural forces have become more extreme due to climate change, permanently altering beaches at very ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Erosion
Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is distinct from weathering which involves no movement. Removal of rock or soil as clastic sediment is referred to as ''physical'' or ''mechanical'' erosion; this contrasts with ''chemical'' erosion, where soil or rock material is removed from an area by dissolution. Eroded sediment or solutes may be transported just a few millimetres, or for thousands of kilometres. Agents of erosion include rainfall; bedrock wear in rivers; coastal erosion by the sea and waves; glacial plucking, abrasion, and scour; areal flooding; wind abrasion; groundwater processes; and mass movement processes in steep landscapes like landslides and debris flows. The rates at which such processes act control how fast a surface is eroded. Typically, physical ero ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
