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Valcouroceratidae
The Valcouroceratidae is a family within the Oncocerida, nautiloid cephalopods from the middle and upper Ordovician, established by Rousseau Flower in 1945. Diagnosis Valcouroceratids are characterized by exogastric cyrtocones and brevicones that change during the life span from compressed to depressed or subtriangular in cross section, and which have ventral siphuncles that are cyrtochoanitic and which contain lamellar actinosiphonate fillings. The actinosiphonate fillings, commonly referred to as deposits, are radially inward projections of the connecting rings that extend longitudinally along the inner wall of the siphuncle and project forward as blades into the siphuncle interior from the septal foramina.(Sweet 1964, Flower 1950) Distribution Most valcouroceratids come from North America but Valcouroceras has been found in northern Europe (Norway) as well. (Sweet 1964) Genera The Valcouroceratidae includes 8 genera: *'' Valcouroceras'' *'' Actinomorpha'' *'' Augustoceras'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kindleoceras
''Kindleoceras'' is a genus of oncocerids belonging to the Valcouroceratidae, extinct nautiloid cephalopods that lived during the Middle and Late Ordovician. ''Kindleoceras'' is characterized by a gently curved or virtually straight shell, the cross section of which is triangular with flattened dorsum and subangular venter. The siphuncle is small, ventral, cyrtochoanitic with outwardly flared necks, thickened rings, and well developed radial internal actinosiphonate deposits. In general form ''Kindleoceras ''is similar to '' Manitoulinoceras'' except for its triangular cross section. '' Augustoceras'', another valcouroceratid, differs in that the rays in its actinosiphonate deposits are longer but less numerous. ''Kindleoceras'', named by Foeste, has been found in the Middle and Upper Ordovician of Ontario Ontario ( ; ) is one of the thirteen provinces and territories of Canada.Ontario is located in the geographic eastern half of Canada, but it has historically and polit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Minganoceras
''Minganoceras'' is a genus in the oncocerid family, Valcouroceratidae, named by Foeste, 1938, from the Middle Ordovician of Quebec, found on Mingan Island. The shell of ''Minganoceras'' is a slender depressed exogastric cyrtocone, curved so that the underside, the venter, is longitudinally convex and the opposite side, the dorsum, is longitudinally concave. The venter is more narrowly rounded in section than the dorsum, a common feature of exogastric forms, including ''Bassleroceras'' and developed to a greater extreme in ''Kindleoceras ''Kindleoceras'' is a genus of oncocerids belonging to the Valcouroceratidae, extinct nautiloid cephalopods that lived during the Middle and Late Ordovician. ''Kindleoceras'' is characterized by a gently curved or virtually straight shell, the ...''. The siphuncle is cyrochoanitic with simple actinosiphonate deposits. References * Walter C Sweet, 1964. Nautiloidea-Oncocerida. Treatise on Invertebrate Paleontology Part K Mollusca 3. Geologi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Valcouroceras
''Valcouroceras'' is the type genus for the Valcouroceratidae, a family in the nautiloid order Oncocerida named by Rousseau Flower, 1943, named for Valcour Island in Lake Champlain, between New York state and Vermont, where it was first discovered. The shell of ''Valcouroceras'' is strongly curved, more so than in ''Minganoceras'', with the lower or ventral side on the outside curve. The body, or living, chamber is gibbous, broader near the middle than at the ends. The early growth stage is laterally compressed, higher than wide, then dorsally flattened, and finally depressed, wider than high. Septal necks of the 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 ... are straight, suborthochoanitic, nearly reaching he previous septa. Connecting rings start off thin but thick ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Actinomorpha
''Actinomorpha'' is a genus of valcouroceratid, order Oncocerida, from the Middle Ordovician of central North America (Minnesota, Wisconsin), named by Rousseau Flower, 1943. The shell is breviconic, short and laterally compressed; the venter more narrowly rounded than the dorsum, having the effect of a modest keel in horizontal orientation. The shell is gibbous adorally, such that the body chamber is widest well behind the aperture. The siphuncle is ventral, which could also be indicative of a horizontal orientation in life, with broad, slightly inflated segments and continuous, radial, actinosiphonate, deposits. While ''Actinomorpha'' is a member of the Oncocerida; ''Actinoceras'' with its somewhat similar name belongs to the Actinocerida The Actinocerida are an order of generally straight, medium to large cephalopods that lived during the early and middle Paleozoic, distinguished by a siphuncle composed of expanded segments that extend into the adjacent chambers, in which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Augustoceras
''Augustoceras'' is a genus of nautiloid cephalopods included in the order Oncocerida and family Valcouroceratidae. It is known form the Middle and Upper Ordovician of Kentucky and Ohio in the US. Shells of ''Augustocers'' are slender, upwardly curved, fusiform, exogastric cyrtocones with subtriangular cross-sections, short chambers, oblique sutures, and subventral siphuncles with simple internal radial actinosiphonate deposits. ''Kindleoceras'' from the Upper Ordovician The Ordovician ( ) is a geologic period and system, the second of six periods of the Paleozoic 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 ... of Ontario differs in having a more triangular cross-section and more numerous actinosiphonate rays in its siphuncle. References *Walter C Sweet, 1964 Nautiloidea-Oncocerida. Treatise on Invertebrate Paleontology Part K Mollusca 3. Geological Society of America ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fayettoceras
''Fayettoceras'' is a genus in the nautiloid family Valcouroceratidae, part of the order Oncocerida, ''Fayettoceras'' has a shell which is a depressed cyrtocone with a ventral cyrtochoanitic 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 ... of elongated ovoid segments strongly contracted at the septal necks. The internal structure is unknown. ''Fayettoceras'' was named by Foeste in 1932. Its fossils have been found in the Upper Ordovician of Indiana and ?Wisconsin in the United States. References * Walter C Sweet, 1964 Nautiloidea-Oncocerida. Treatise on Invertebrate Paleontology Part K Mollusca 3. Geological Society of America and University of Kansas Press. Prehistoric nautiloid genera Oncocerida {{paleo-nautiloidea-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oncocerida
The Oncocerida comprise a diverse group of generally small nautiloid cephalopods known from the Middle Ordovician to the Mississippian (early Carboniferous; one possible member is known from the Early Permian), in which the connecting rings are thin and siphuncle segments are variably expanded (Flower, 1950). At present the order consists of some 16 families, a few of which, such as the Oncoceratidae, Brevicoceratidae, and Acleistoceratidae contain a fair number of genera each while others like the Trimeroceratidae and Archiacoceratidae are represented by only two or three (Sweet, 1964). Physical characteristics The shells of oncocerids are primarily somewhat compressed cyrtoconic brevicones. More advanced forms include gyrocones, serpenticones, torticones, and elongate orthocones and cyrtocones, reflective of the different families and genera (Flower, 1950; Sweet, 1964). The siphuncle in the Oncocerida is commonly located at or near the ventral margin. Connecting rings are mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Ordovician Extinctions
Late may refer to: * LATE, an acronym which could stand for: ** Limbic-predominant age-related TDP-43 encephalopathy, a proposed form of dementia ** Local-authority trading enterprise, a New Zealand business law ** Local average treatment effect, a concept in econometrics Music * ''Late'' (album), a 2000 album by The 77s * Late!, a pseudonym used by Dave Grohl on his ''Pocketwatch'' album * Late (rapper), an underground rapper from Wolverhampton * "Late" (song), a song by Blue Angel * "Late", a song by Kanye West from ''Late Registration'' Other * Late (Tonga), an uninhabited volcanic island southwest of Vavau in the kingdom of Tonga * "Late" (''The Handmaid's Tale''), a television episode * LaTe, Oy Laivateollisuus Ab, a defunct shipbuilding company * Late may refer to a person who is Dead See also * * * ''Lates'', a genus of fish in the lates perch family * Later (other) * Tardiness * Tardiness (scheduling) In scheduling, tardiness is a measure of a delay in exe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Middle Ordovician First Appearances
Middle or The Middle may refer to: * Centre (geometry), the point equally distant from the outer limits. Places * Middle (sheading), a subdivision of the Isle of Man * Middle Bay (other) * Middle Brook (other) * Middle Creek (other) * Middle Island (other) * Middle Lake (other) * Middle Mountain, California * Middle Peninsula, Chesapeake Bay, Virginia * Middle Range, a former name of the Xueshan Range on Taiwan Island * Middle River (other) * Middle Rocks, two rocks at the eastern opening of the Straits of Singapore * Middle Sound, a bay in North Carolina * Middle Township (other) * Middle East Music * "Middle" (song), 2015 * "The Middle" (Jimmy Eat World song), 2001 * "The Middle" (Zedd, Maren Morris and Grey song), 2018 *"Middle", a song by Rocket from the Crypt from their 1995 album ''Scream, Dracula, Scream!'' *"The Middle", a song by Demi Lovato from their debut album ''Don't Forget'' *"The Middle", a song by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ordovician Cephalopods
The Ordovician ( ) is a geologic period and system, the second of six periods of the Paleozoic 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 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 beds in North Wales in the Cambrian and Silurian systems, respectively. Lapworth recognized that the fossil fauna in the disputed 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 Geological Congress. Life continued to flourish during the Ordovician as it did in the earlier Cambr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prehistoric Nautiloid Families
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] |
Treatise On Invertebrate Paleontology
The ''Treatise on Invertebrate Paleontology'' (or ''TIP'') published by the Geological Society of America and the University of Kansas Press, is a definitive multi-authored work of some 50 volumes, written by more than 300 paleontologists, and covering every phylum, class, order, family, and genus of fossil and extant (still living) invertebrate animals. The prehistoric invertebrates are described as to their taxonomy, morphology, paleoecology, stratigraphic and paleogeographic range. However, taxa with no fossil record whatsoever have just a very brief listing. Publication of the decades-long ''Treatise on Invertebrate Paleontology'' is a work-in-progress; and therefore it is not yet complete: For example, there is no volume yet published regarding the post-Paleozoic era caenogastropods (a molluscan group including the whelk and Common periwinkle, periwinkle). Furthermore, every so often, previously published volumes of the ''Treatise'' are revised. Evolution of the proje ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
