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Lituitina
Lituitida is an order of orthoceratoid cephalopods. They correspond to the family Lituitidae of the Treatise (Furnish & Glenister, 1964), reranked as an order and combined with other orthoceratoids. They are considered to be more closely related to the Orthocerida than to the Ascocerida or Pseudorthocerida which are also included. Lituitids are characterized by smooth to annulate shells in which the juvenile portion near the apex is coiled or cyrtoconic. The adult portion is straight or slightly sigmoidal and may be expanded. Growth lines show a deep hyponomic sinus and lateral ocular sinuses. The siphuncle is subcentral with layered connecting rings. Cameral deposits are prevalent and concentrated more ventrally. The apex is small and spherical and lacks a cicatrix. The Lituitida, which were originally included in the Tarphycerida as the Lituitidae (Furnish and Glenister) have their beginnings in the Early Ordovician with forms like ''Ancistroceras''. Their diversity increase ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orthoceratoidea
Orthoceratoidea, from Ancient Greek ὀρθός (''orthós''), meaning "straight", and κέρας (''kéras''), meaning "horn", is a major subclass of nautiloid cephalopods. Members of this subclass usually have orthoconic (straight) to slightly cyrtoconic (curved) shells, and central to subcentral siphuncles which may bear internal deposits. Orthoceratoids are also characterized by dorsomyarian muscle scars (a small number of large scars concentrated at the top of the body chamber), extensive cameral deposits, and calciosiphonate connecting rings with a porous and calcitic inner layer. Currently, Orthoceratoidea comprises the orders Riocerida, Dissidocerida, Actinocerida, Pseudorthocerida, Lituitida and Orthocerida. Orthocerida is a noteworthy paraphyletic order which is ancestral to the major cephalopod groups such as the extinct ammonoids and living coleoids (cephalopods without external shells, including squids, octopus, cuttlefish, etc.). Taxonomy As a superorder, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cephalopod
A cephalopod is any member of the molluscan Taxonomic rank, class Cephalopoda (Greek language, Greek plural , ; "head-feet") such as a squid, octopus, cuttlefish, or nautilus. These exclusively marine animals are characterized by bilateral symmetry, bilateral body symmetry, a prominent head, and a set of cephalopod arm, arms or tentacles (muscular hydrostats) modified from the primitive molluscan foot. Fishers sometimes call cephalopods "inkfish", referring to their common ability to squirt Cephalopod ink, ink. The study of cephalopods is a branch of malacology known as teuthology. Cephalopods became dominant during the Ordovician period, represented by primitive nautiloids. The class now contains two, only distantly related, Extant taxon, extant subclasses: Coleoidea, which includes octopuses, squid, and cuttlefish; and Nautiloidea, represented by ''Nautilus (genus), Nautilus'' and ''Allonautilus''. In the Coleoidea, the molluscan shell has been internalized or is absent, where ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orthocerida
Orthocerida, from Ancient Greek ὀρθός (''orthós''), meaning "straight", and κέρας (''kéras''), meaning "horn", also known as the Michelinocerida, is an order of extinct Orthoceratoidea, orthoceratoid cephalopods that lived from the Early Ordovician () possibly to the Late Triassic (). A Zhuravlevia, fossil found in the Caucasus suggests they may even have survived until the Early Cretaceous (), and the Eocene fossil ''Antarcticeras'' is sometimes considered a descendant of the orthocerids although this is disputed. They were most common however from the Ordovician to the Devonian. Shell form The shell is usually long, and may be straight ("Orthocone, orthoconic") or gently curved. In life, these animals may have been similar to the modern squid, except for their long shell. The internal structure of the shell consists of concavo-convex Camera (anatomy), chambers linked by a centrally-placed tube called a siphuncle. There is a tendency for the chambers to develop c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ascocerida
The Ascocerida are comparatively small, bizarre Orthoceratoids known only from Ordovician and Silurian sediments in Europe and North America, uniquely characterized by a deciduous conch consisting of a longer juvenile portion and an inflated short adult portion that separate sometime in maturity.W.M . Furnish and Brian F Glenister; Nautiloidea-Ascocerida, K261-K277; Treatise on Invertebrate Paleontology, part K, Nautiloidea; Geological Society of America and the University of Kansas Press, 1964 Morphology The juvenile portion of an ascocerid consists typically of a narrow, circular cyrtocone that underwent periodic truncation. Cumulative length, including broken off segments, may have reached about in the largest individuals. The siphuncle is located halfway between the shell axis and the venter, is thin walled and tubular with short, orthochoanitic septal necks and segments that are only slightly inflated. The juvenile portion is known as the deciduous conch, as it is shed in a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pseudorthocerida
Pseudorthocerida is an order of generally straight longiconic (consisting of longicones - long, thin conic shells) orthoceratoids with a subcentral to marginal cyrtochoanitic siphuncle composed of variably expanded segments which may contain internal deposits that may develop into a continuous parietal lining. (Sweet 1964). Cameral deposits are common and concentrated ventrally. Apices typically have a slight to moderate exogastric curvature The Pseudorthocerida are included in a broad in-group of generally orthoconic cephalopods known as the Orthoceratoidea (Kroger 2008) along with the Ascocerida, Dissidocerida, Lituitida, and Orthocerida. The Pseudorthocerida were among the last living orthoconic nautiloids. One family, the Trematoceratidae, survived into the Triassic Period. Taxonomy Current understanding By current understanding the Pseudorthocerida contains the following families: * Pseudorthoceratidae * Cayutoceratidae * Pseudactinoceratidae * Spyroceratidae * Carb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Connecting Ring
''Connecting...'' is an American television sitcom co-created and co-executive produced by Martin Gero and Brendan Gall for Universal Television. The series aired from October 8 to October 29, 2020 on NBC. In November 2020, the series was canceled after four episodes. The remaining episodes were released on NBC.com and Peacock shortly after. Premise Set against the backdrop of the COVID-19 pandemic in the United States, the series follows the lives of a group of friends who try to stay connected via videotelephony as they navigate through the various nuances of life in a lockdown. Cast Main *Otmara Marrero as Annie *Parvesh Cheena as Pradeep *Keith Powell as Garrett *Jill Knox as Michelle *Shakina Nayfack as Ellis *Ely Henry as Rufus * Preacher Lawson as Ben Recurring * Cassie Beck as Jazmin * Loretta Devine as Dayleen * Alex Landi as Cameron Guest *Constance Marie as Martha *Tony Plana as Ramona *Carl Tart as Wendell *Jaime Cepero as Kirby *D'Lo as Zach Episodes Product ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ancistroceras
''Ancistroceras'' is one of the two ancestral lituitids from the late Early Ordovician (Arenigian). The other being '' Holmiceras''. The shell is weakly annulate, starts off with 1.5 to 2 contiguous or slightly separated whorls followed by a rapidly expanding orthocone with an apical angle of about 30 deg. Growth lines are sinuous, show a pronounced hyponomic sinus in the coiled juvenile portion at the apex but almost none at the mature aperture of the orthcone. ''Holmiceras'' is similar except that its whorls are more loosely coiled and it is known only from the Arenigian whereas ''Ancistroceras'' ranges through most of the Middle Ordovician. ''Ancistroceras'' may have given rise to '' Rhynchorthoceras'' by a loss of the juvenile coiled portion, replacing it with a short semi-tubular cyrtoconic section. ''Ancistroceras'' may also have given rise to ''Lituites'' by evolving a narrower, less rapidly expanding, orthocone along with greater ornament and a complex aperture. Referen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canadian Epoch
{{Short description, Lower or Early Ordovician in North America The Canadian is the Lower or Early Ordovician in North America. The term is common in the older literature and has been well understood for more than a century. However it has no official recognition by the International Commission on Stratigraphy (ICS) and has been superseded by the more recently defined Ibexian series of western Utah. Background Dana introduced the Canadian as the name for a system separated from the rest of the Ordovician (Weller 1980), then known as the Lower Silurian, and referred to the rest of the Lower Silurian as the Trenton System. At that time the Ordovician had not yet been recognized. Later Ulrich redefined the Canadian as roughly equivalent to the Beekmantown strata of the Lower Ordovician. Flower (1957 p. 17) felt that recognition of the Canadian as a separate system would greatly solve problems in Early Paleozoic stratigraphy. As such, faunas in limestones of Canadian age are unifo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lituites
''Lituites'' is an extinct nautiloid genus from the Middle Ordovician and type for the Lituitidae (a tarphycerid family) that in some more recent taxonomies has been classified with the orthocerids and listed under the order Lituitida. Fossils have been found in New York, Argentina, Norway, Sweden, Estonia, and China. ''Lituites'' produced a shell with a planospirally coiled juvenile portion at the apex, reflective of its tarphycerid ancestry, followed by a long, moderately expanding, generally straight, orthoconic adult section with a subdorsal siphuncle connecting the chambers. The adult body chamber may equal or exceed the length of the chambered part of the orthoconic section. The mature aperture has a pair of pronounced ventrolateral lappets and a similar but shorter pair of dorsolateral lappets. ''Lituites'' gives its name to the term "lituiticone" which refers to a shell that is coiled in the early growth stage and later becomes uncoiled. References *Fl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Swiss Journal Of Palaeontology
The ''Swiss Journal of Palaeontology'' is a biannual open access peer-reviewed scientific journal covering palaeontology and taxonomy published by BioMed Central. It is affiliated with the Swiss Geological Society and a member of the Swiss Academy of Sciences. History The journal was established as ''Schweizerische Paläontologische Abhandlungen'' in 1874 and was published by the Natural History Museum of Basel. In 2011, it was relaunched as the ''Swiss Journal of Palaeontology'' and publisher became BioMed Central. Since 2020 the journal is open access. Abstracting and indexing The journal is abstracted and indexed in: According to the ''Journal Citation Reports'', the journal has a 2023 impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a type of journal ranking. Journals with higher impact factor values are considered more prestigious or important within their field. The Impact Factor of a journa ... of 3.0. References Exte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
