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Plectoceras
''Plectoceras'' is a genus of nautiloids included in the tarphycerid suborder Barrandeocerina that lived during the Middle and Late Ordovician. It has been found widespread in the Middle and Upper Ordovician of North America. ''Plectoceras'' has a coiled, costate shell with a perforate (see-through) umblilcus; whorls are dorsally impressed by end of first volution but loosen in the adult stage with the mature body chamber diverging from the adjacent whorl. Costae (ribs) slope dorso-ventrally toward the apex and sutures are straight or have lateral lobes. The siphuncle is subventral, orthochoanitic with short, straight necks and thin connecting rings. ''Plectoceras'' and its contemporary ''Barrandeoceras'' are both likely derived from the Tarphyceratidae; ''Plectoceras'' with its subventral siphuncle possibly from ''Campbelloceras ''Campbelloceras'' is a tarphyceratid nautiloid known from the Lower Ordovician, Upper Canadian Epoch of North America, where it is widespread. ''Ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Campbelloceras
''Campbelloceras'' is a tarphyceratid nautiloid known from the Lower Ordovician, Upper Canadian Epoch of North America, where it is widespread. ''Campbelloceras'' was named by Ulrich and Foerste in 1936. The shell of ''Campbelloceras'' has a circular whorl section, only slightly impressed, and a siphuncle that is close to the venter in all growth stages. ''Campbelloceras'' differs from ''Tarphyceras'' in that the rate of expansion is greater, the siphuncle is proportionally largers, and an impression is shallower. ''Campbelloceras'' may have given rise to the barrandeocerid ''Plectoceras'' ( Plectoceratidae) through simplification of the connecting rings, and to ''Tarphyceras'' through tighter coiling, development of a deeper impression, and reduction in the size of the siphuncle. ''Campbelloceras'' may be conceivably derived from ''Estonioceras'' (Estonioceratidae). The cross section of ''Campbelloceras'' and that of the outer whorl of ''Estonioceras'' are similar, except fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 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 C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nautiloidea
Nautiloids are a group of marine cephalopods ( Mollusca) which originated in the Late Cambrian and are represented today by the living ''Nautilus'' and '' Allonautilus''. Fossil nautiloids are diverse and speciose, with over 2,500 recorded species. They flourished during the early Paleozoic era, when they constituted the main predatory animals. Early in their evolution, nautiloids developed an extraordinary diversity of shell shapes, including coiled morphologies and giant straight-shelled forms (orthocones). Only a handful of rare coiled species, the nautiluses, survive to the present day. In a broad sense, "nautiloid" refers to a major cephalopod subclass or collection of subclasses (Nautiloidea ''sensu lato''). Nautiloids are typically considered one of three main groups of cephalopods, along with the extinct ammonoids (ammonites) and living coleoids (such as squid, octopus, and kin). While ammonoids and coleoids are monophyletic clades with exclusive ancestor-descendant re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barrandeocerina
The Barrandeocerina comprise a suborder of Early Paleozoic nautiloid cephalopods, primitively coiled but later forms may be cyrtoconic, gyroconic, torticonic, and even breviconic, all having empty siphuncles with thin connecting rings. The Barrandeocerina were originally defined as a separate order by Rousseau Flower (Flower and Kummel, 1950), but since then have been united within the Tarphycerida as a suborder (Teichert 1988). Derivation is from the Tarphyceratidae. In early forms the siphuncle is central or subcentral, orthochoanitic (septal necks short and straight), and thin, with tubular segments. Later forms include those with cyrtochoanitic septal necks (curved outward) and segments that may be slightly to strongly expanded into the chambers. Taxonomy Six families are included in the Barrandeocerina, (ex Barrandeocerida). :Barrandeoceratidae M Ord-M Dev : Plectoceratidae M-U Ord : Apsidoceratidae M-U Ord :Uranoceratidae U Ord-M Sil :Lechritrochoceratidae M-U Sil : ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barrandeoceras
''Barrandeoceras'' is a large, coiled, Middle Ordovician nautiloid cephalopod and part of the Tarphycerida. The shell is serpenticonic with whorls touching but not embracing. The adult body chamber becomes freed of the preceding whorl, a rather common character among tarphycerids. Whorl section is oval, somewhat more narrowly rounded ventrally, on the outer rim, than dorsally, on the inner rim. Prominent lateral ribs, at least on inner whorls. Grow lines show a distinct hyponomic sinus. Sutures have lateral lobes. The siphuncle is subcentral. Barrandeoceras has been found in the Middle Ordovician of New York, Ontario, and Quebec. It is the type genus for the Barrandeoceratidae The Barrandeoceratidae is a family of coiled nautiloids included in the Tarphycerida (''sensu lato'') that lived from the Middle Ordovician to the Middle Devonian, characterised by mostly compressed shells with a subcentral siphuncle composed of .... References *Rousseau H Flower and Bernhard Kümmel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tarphyceratidae
The Tarphyceratidae are tightly coiled, evolute Tarphycerida with ventral siphuncles. The dorsum is characteristically impressed where the whorl presses against the venter of the previous. The Tarphyceratidae are derived from '' Bassleroceras'' or possibly from some member of the Estonioceratidae. Tarphyceratids vary in form and siphuncle position. The siphuncle may be subcentral as in ''Centrotarphyceras''; intermediary as in '' Tarphyceras'', or subventral as in '' Campbelloceras''. Cross sections vary. ''Tarphyceras'' and ''Campbelloceras'' are rounded. ''Centrotarphyceras'' is subquadrate with broadly rounded flanks and a slightly rounded venter. ''Eurystomites'' is subquadrate and slightly compressed, with the maximum width closer to the dorsum. ''Pionoceras'' is subrounded and slightly depressed with the maximum width closer to the venter. The dorsal impression in ''Tarphyceras'' and ''Eurystomites'' is broad and deep and in ''Pionoceras'' and ''Centrotarphyceras'', broad a ... [...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. ... [...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 Cambri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ordovician Cephalopods Of North America
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 Cambrian ... [...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 ... [...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), ''Late'' (album), a 2000 album by The 77s * Late!, a pseudonym used by Dave Grohl on his ''Pocketwatch (album), Pocketwatch'' album * Late (rapper), an underground rapper from Wolverhampton * Late (song), "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), "Late" (''The Handmaid's Tale''), a television episode * LaTe, Laivateollisuus, 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) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
