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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] |
James River
The James River is a river in the U.S. state of Virginia that begins in the Appalachian Mountains and flows U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map , accessed April 1, 2011 to Chesapeake Bay. The river length extends to if one includes the Jackson River, the longer of its two source tributaries. It is the longest river in Virginia. Jamestown and Williamsburg, Virginia's first colonial capitals, and Richmond, Virginia's current capital, lie on the James River. History The Native Americans who populated the area east of the Fall Line in the late 16th and early 17th centuries called the James River the Powhatan River, named for the chief of the Powhatan Confederacy which extended over most of the Tidewater region of Virginia. The Jamestown colonists who arrived in 1607 named it "James" after King James I of England (), as they constructed the first permanent English settlement in the Americas at Jamestown alo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Croatan Formation
The Croatan Formation is a geologic formation in North Carolina. It preserves fossils dating back to the Neogene period. See also * List of fossiliferous stratigraphic units in North Carolina This article contains a list of fossil-bearing stratigraphic units in the state of North Carolina, U.S. Sites See also * Paleontology in North Carolina * Lists of fossiliferous stratigraphic units in the United States References * {{ ... References * Neogene geology of North Carolina {{Neogene-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cerastoderma
''Cerastoderma'' is a genus of marine bivalves in the family Cardiidae. It includes the common cockle ''Cerastoderma edule.'' Fossil records This genus is known in the fossil records from the Paleocene to the Quaternary (age range: from 58.7 to 0.012 million years ago). Species Extant species: * ''Cerastoderma edule'' (Linnaeus, 1758) - common cockle * ''Cerastoderma glaucum ''Cerastoderma glaucum'', the lagoon cockle, is a species of saltwater clam, a marine bivalve mollusc in the family Cardiidae, the cockles. This species is found along the coasts of Europe and North Africa, including the Mediterranean and Black ...'' (Poiret, 1789) - lagoon cockle :: (= ''Cerastoderma lamarcki'' eeve, 1845 Fossil taxa: * '' Cardium (Cerastoderma) calvertensium ''Glenn, 1904 † * '' Cardium (Cerastoderma) patuxentium'' Glenn, 1904 † * '' Cardium (Cerastoderma) waltonianum'' Dall, 1900 † * '' Cerastoderma chipolanum'' Dall, 1900 † * '' Cerastoderma latisulcum'' † * '' Cerast ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Noetiidae
Noetiidae is a family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ... of saltwater clams, marine bivalve molluscs in the order Arcida. They are related to the ark clams and used to be classified as among them. They are differentiated from the ark clams by the presence of striations on the hinge ligament and on the placement of this ligament. Like the ark clams, however, their shells range from ovate to elongate, are inflated, and are brown and white with clear radial ribs. They usually grow to around 6 cm in length, with a maximum of 10 cm. Genera and species Genera and species within the family Noetidae include: * '' Arcopsis'' Koenen, 1885 ** ''Arcopsis adamsi'' (Dall, 1886) ** ''Arcopsis fossularca'' ** ''Arcopsis gabinarca'' ** ''Arcopsis mulinarca'' ** ''A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ensis
''Ensis'' is a genus of medium-sized edible saltwater clams, littoral bivalve molluscs in the family Pharidae. ''Ensis'', or razor clams, are known in much of Scotland as spoots, for the spouts of water they eject while burrowing into the sand, when visible at low tide. This term may also colloquially include members of the genus '' Solen''. '' Ensis magnus'' are known as bendies due to their slightly curved shell. Description The shells are long, narrow, and parallel-sided. This shape resembles a closed, old-fashioned straight razor (a cut-throat razor), or a closed jackknife (pocket knife) and sometimes these clams are known as razor shells or jackknives. The shells in these species are fragile and can easily be damaged when digging for these clams. Ecology ''Ensis'' species live in clean sand on exposed beaches. They are capable of digging very rapidly; see the description under the Atlantic jackknife clam. Some clammers catch jackknives by pouring salt on the characteri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chama (bivalve)
''Chama'' is a genus of cemented saltwater clams, marine bivalve molluscs in the family Chamidae, the jewel boxes. Species Extant species within this genus include: * '' Chama ambigua'' Lischke, 1870 * '' Chama arcana'' F. R. Bernard, 1987 * '' Chama asperella'' Lamarck, 1819 * '' Chama brassica'' Reeve, 1847 * '' Chama buddiana'' C.B. Adams, 1852 * '' Chama cerinorhodon'' Hamada & Matsukuma, 2005 * '' Chama cerion'' Matsukuma, Paulay & Hamada, 2003 * '' Chama circinata'' di Monterosato, 1878 * '' Chama congregata'' Conrad, 1833 * '' Chama coralloides'' Reeve, 1846 * '' Chama crenulata'' Lamarck, 1819 * '' Chama croceata'' Lamarck, 1819 * '' Chama dunkeri'' Lischke, 1870 * '' Chama echinata'' Broderip, 1835 * '' Chama florida'' Lamarck, 1819 * '' Chama frondosa'' Broderip, 1835 * '' Chama gryphoides'' Linnaeus, 1758 * '' Chama hicksi'' Valentich-Scott & Coan, 2010 * '' Chama isaacooki'' Healy, Lamprell & Stanisic, 1993 * '' Chama lactuca'' Dall, 1886 * '' Chama lazarus'' Linnaeus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mercenaria
''Mercenaria'' is a genus of edible saltwater clams, marine bivalve molluscs in the family Veneridae, the Venus clams. The genus ''Mercenaria'' includes the quahogs, consisting of ''Mercenaria mercenaria'', the northern quahog or hard clam, and ''M. campechiensis'', the southern quahog. These two species commonly hybridise where their ranges overlap. Mercenaria mercenaria is further subdivided in the marketplace and thence in the kitchen by size: the largest being the quahog or chowder clam, then smaller cherrystones, and smallest littlenecks; some markets also differentiate top necks which are intermediate in size between cherrystones and littlenecks. The smaller clams are eaten raw throughout New England, New York, and New Jersey; the larger clams are more suited for cooking. Other species within the genus include the venus clam ''M. stimpsoni'' found in north Pacific waters. All these species were formerly placed in the related genus ''Venus''. Species The World Register ... [...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] |
Glycymerididae
Glycymerididae, often misspelled as Glycymeridae, common names dog cockles or bittersweets, is a worldwide family of salt water clams, marine bivalve mollusks in the order Arcida. They are related to the ark clams. This family contains 45 extant species in four genera. Description In this family the shell is generally round in outline and is slightly longer than it is wide. The external ligament lacks transverse striations. The shell in some genera is smooth and in others it is ribbed. History of the name Authority of Glycymerididae has been incorrectly attributed to Newton (1916 or 1922) by a great number of authors. While Newton was the first to publish this name, Dall (1908) had previously established the subfamily Glycymerinae , which gives him priority for the family name under Article 36 of ICZN. The name comes from the Ancient Greek word ''glykymaris'' (perhaps from ''glykýs'' "sweet" and ''méros'' "part"), a word which is only recorded once in Greek literature. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Foraminifera
Foraminifera (; Latin for "hole bearers"; informally called "forams") are single-celled organisms, members of a phylum or class of amoeboid protists characterized by streaming granular ectoplasm for catching food and other uses; and commonly an external shell (called a "test") of diverse forms and materials. Tests of chitin (found in some simple genera, and Textularia in particular) are believed to be the most primitive type. Most foraminifera are marine, the majority of which live on or within the seafloor sediment (i.e., are benthic), while a smaller number float in the water column at various depths (i.e., are planktonic), which belong to the suborder Globigerinina. Fewer are known from freshwater or brackish conditions, and some very few (nonaquatic) soil species have been identified through molecular analysis of small subunit ribosomal DNA. Foraminifera typically produce a test, or shell, which can have either one or multiple chambers, some becoming quite elaborate in s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biostratigraphy
Biostratigraphy is the branch of stratigraphy which focuses on correlating and assigning relative ages of rock strata by using the fossil assemblages contained within them.Hine, Robert. “Biostratigraphy.” ''Oxford Reference: Dictionary of Biology'', 8th ed., Oxford University Press, 2019. The primary objective of biostratigraphy is ''correlation'', demonstrating that a particular horizon in one geological section represents the same period of time as another horizon at a different section. Fossils within these strata are useful because sediments of the same age can look completely different, due to local variations in the sedimentary environment. For example, one section might have been made up of clays and marls, while another has more chalky limestones. However, if the fossil species recorded are similar, the two sediments are likely to have been laid down around the same time. Ideally these fossils are used to help identify biozones, as they make up the basic biostratig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ostracod
Ostracods, or ostracodes, are a class of the Crustacea (class Ostracoda), sometimes known as seed shrimp. Some 70,000 species (only 13,000 of which are extant) have been identified, grouped into several orders. They are small crustaceans, typically around in size, but varying from in the case of '' Gigantocypris''. Their bodies are flattened from side to side and protected by a bivalve-like, chitinous or calcareous valve or "shell". The hinge of the two valves is in the upper (dorsal) region of the body. Ostracods are grouped together based on gross morphology. While early work indicated the group may not be monophyletic and early molecular phylogeny was ambiguous on this front, recent combined analyses of molecular and morphological data found support for monophyly in analyses with broadest taxon sampling. Ecologically, marine ostracods can be part of the zooplankton or (most commonly) are part of the benthos, living on or inside the upper layer of the sea floor. While ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
