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Nanno (cephalopod)
''Nanno'' is an extinct genus of Endocerid, named by Clarke in 1894 for the apical end of an endocerid from the Trenton Limestone of New York state that has the basic description of the nanno type (where the siphuncle swells to fill the entire apex of the shell, leaving septa and camerae to begin a few centimeters forward). It is possibly the senior synonym for ''Proterovaginoceras'' . As a valid genus, ''Nanno'' is included in the Endoceratidae Endoceratidae is a family of large to very large straight shelled nautiloid cephalopods belonging to the order Endocerida that lived during the Middle and Late Ordovician. They include the largest known Paleozoic invertebrates, represented by '' ... but the nanno type apex may be found in other families. References * Clarke, J. M. (1897)The Lower Silurian Cephalopoda of Minnesota In: E.O. Ulrich, J. M. Clarke, W. H. Scofield & N. H. Winchell ''The Geology of Minnesota. Vol. III, Part II, of the final report. Paleontology.'' Harriso ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ordovician
The Ordovician ( ) is a geologic period and System (geology), system, the second of six periods of the Paleozoic Era (geology), Era. The Ordovician spans 41.6 million years from the end of the Cambrian Period million years ago (Mya) to the start of the Silurian Period Mya. The Ordovician, named after the Celtic Britons, Welsh tribe of the Ordovices, was defined by Charles Lapworth in 1879 to resolve a dispute between followers of Adam Sedgwick and Roderick Murchison, who were placing the same Rock (geology), rock beds in North Wales in the Cambrian and Silurian systems, respectively. Lapworth recognized that the fossil fauna in the disputed Stratum, strata were different from those of either the Cambrian or the Silurian systems, and placed them in a system of their own. The Ordovician received international approval in 1960 (forty years after Lapworth's death), when it was adopted as an official period of the Paleozoic Era by the International Union of Geological Sciences, Intern ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endocerid
Endocerida is an extinct Nautiloidea, nautiloid order, a group of cephalopods from the Lower Paleozoic with cone-like deposits in their siphuncle. Endocerida was a diverse group of cephalopods that lived from the Early Ordovician possibly to the Late Silurian. Their shells were variable in form. Some were straight (orthoconic), others curved (cyrtoconic); some were long (longiconic), others short (breviconic). Some long-shelled forms like ''Endoceras'' attained shell lengths close to . The related ''Cameroceras'' is anecdotally reported to have reached lengths approaching , but these claims are problematic. The overwhelming majority of endocerids and nautiloids in general are much smaller, usually less than a meter long when fully grown. Morphology Endocerids had a relatively small body chamber as well as a proportionally large siphuncle, which in some genera reached nearly half the shell diameter. This suggests that much of the visceral mass may have been housed within the sip ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anatomical Terms Of Location
Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position provides a definition of what is at the front ("anterior"), behind ("posterior") and so on. As part of defining and describing terms, the body is described through the use of anatomical planes and anatomical axes. The meaning of terms that are used can change depending on whether an organism is bipedal or quadrupedal. Additionally, for some animals such as invertebrates, some terms may not have any meaning at all; for example, an animal that is radially symmetrical will have no anterior surface, but can still have a description that a part is close to the middle ("proximal") or further from the middle ("distal"). International organisations have determined vocabularies that are often used as standard vocabularies for subdisciplines of anatom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endocerida
Endocerida is an extinct nautiloid order, a group of cephalopods from the Lower Paleozoic with cone-like deposits in their siphuncle. Endocerida was a diverse group of cephalopods that lived from the Early Ordovician possibly to the Late Silurian. Their shells were variable in form. Some were straight (orthoconic), others curved (cyrtoconic); some were long (longiconic), others short (breviconic). Some long-shelled forms like '' Endoceras'' attained shell lengths close to . The related ''Cameroceras'' is anecdotally reported to have reached lengths approaching , but these claims are problematic. The overwhelming majority of endocerids and nautiloids in general are much smaller, usually less than a meter long when fully grown. Morphology Endocerids had a relatively small body chamber as well as a proportionally large siphuncle, which in some genera reached nearly half the shell diameter. This suggests that much of the visceral mass may have been housed within the siphuncle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trenton Limestone
The Trenton Formation is a geologic formation in Canada and Michigan, Ohio, and Indiana in the United States. It preserves fossils dating back to the Ordovician period. See also * List of fossiliferous stratigraphic units in Michigan * Trenton Gas Field The Trenton Gas Field is located in east central Indiana and the most western portion of west central Ohio. The field was discovered in 1876, but the size and magnitude of the field was not known until the 1880s. The field was the largest natural g ... * Indiana gas boom * Petroleum industry in Ohio References * Ordovician System of North America Ordovician Michigan Ordovician geology of New York (state) Ordovician geology of Virginia Ordovician southern paleotemperate deposits Middle Ordovician Series {{Michigan-geologic-formation-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Siphuncle
The siphuncle is a strand of tissue passing longitudinally through the shell of a cephalopod mollusk. Only cephalopods with chambered shells have siphuncles, such as the extinct ammonites and belemnites, and the living nautiluses, cuttlefish, and ''Spirula''. In the case of the cuttlefish, the siphuncle is indistinct and connects all the small chambers of that animal's highly modified shell; in the other cephalopods it is thread-like and passes through small openings in the septa (walls) dividing the camerae (chambers). Some older studies have used the term siphon for the siphuncle, though this naming convention is uncommon in modern studies to prevent confusion with a mollusc organ of the same name. Function The siphuncle is used primarily in emptying water from new chambers as the shell grows. To perform this task, the cephalopod increases the saltiness of the blood in the siphuncle, and the water moves from the more dilute chamber into the blood through osmosis. At the sam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synonym (taxonomy)
The Botanical and Zoological Codes of nomenclature treat the concept of synonymy differently. * In botanical nomenclature, a synonym is a scientific name that applies to a taxon that (now) goes by a different scientific name. For example, Linnaeus was the first to give a scientific name (under the currently used system of scientific nomenclature) to the Norway spruce, which he called ''Pinus abies''. This name is no longer in use, so it is now a synonym of the current scientific name, ''Picea abies''. * In zoology, moving a species from one genus to another results in a different binomen, but the name is considered an alternative combination rather than a synonym. The concept of synonymy in zoology is reserved for two names at the same rank that refers to a taxon at that rank - for example, the name ''Papilio prorsa'' Linnaeus, 1758 is a junior synonym of ''Papilio levana'' Linnaeus, 1758, being names for different seasonal forms of the species now referred to as ''Araschnia le ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proterovaginoceras
''Proterovaginoceras'' (Ancient Greek for "earlier shield horn") is a medium to large sized endocerid (endocone-bearing orthoconic nautiliod) from the Early and Middle Ordovician included in the family Endoceratidae Endoceratidae is a family of large to very large straight shelled nautiloid cephalopods belonging to the order Endocerida that lived during the Middle and Late Ordovician. They include the largest known Paleozoic invertebrates, represented by '' .... ''Proterovaginoceras'' has a straight shell with a circular cross section, straight sutures, and a ventral to central, nanno-type, siphuncle which fills the entire apical part of the shell. Septal necks are macrochoanitic, up to two camerae (chambers) long; connecting rings, one chamber in length line the inside of the necks. Endocones are long and slender, fill the entire bulbous, nanno-end, of the siphuncle. ''Proterovaginoceras'' was named by Reudemann in 1905. ''Dideroceras'' Flower 1950 and ''Chisloceras'' Gorta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endoceratidae
Endoceratidae is a family of large to very large straight shelled nautiloid cephalopods belonging to the order Endocerida that lived during the Middle and Late Ordovician. They include the largest known Paleozoic invertebrates, represented by '' Endoceras'' and ''Cameroceras''.Teichert C, (1964). Endoceratoidea; Treatise on Invertebrate Paleontology, ''Part K, Mollusca 3''.Flower R. H. (May 1958). "Some Chazyan and Mohawkian Endoceratida", ''Jour Paleo'' 32 (2) pp 433-458 Description Endocerids are characterized by large, generally ventral siphuncles with simple endocones which lack the more complex structures associated with the Proterocameroceratidae and their derivatives. Endocones, nested cone-shaped deposits characteristic of the Endocerida, form in the apical portion of the siphuncle where they balanced the weight of the animal in the body chamber at the opposite end. This helped assure a horizontal orientation while the endoceratid animal was alive. The septal necks are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prehistoric Nautiloid Genera
Prehistory, also known as pre-literary history, is the period of human history between the use of the first stone tools by hominins 3.3 million years ago and the beginning of recorded history with the invention of writing systems. The use of symbols, marks, and images appears very early among humans, but the earliest known writing systems appeared 5000 years ago. It took thousands of years for writing systems to be widely adopted, with writing spreading to almost all cultures by the 19th century. The end of prehistory therefore came at very different times in different places, and the term is less often used in discussing societies where prehistory ended relatively recently. In the early Bronze Age, Sumer in Mesopotamia, the Indus Valley Civilisation, and ancient Egypt were the first civilizations to develop their own scripts and to keep historical records, with their neighbors following. Most other civilizations reached the end of prehistory during the following Iron Age. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
