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Orthocerida
Orthocerida is an order of extinct Orthoceratoid cephalopods also known as the Michelinocerida that lived from the Early Ordovician () possibly to the Late Triassic (). A fossil found in the Caucasus suggests they may even have survived until the Early Cretaceous (). They were most common however from the Ordovician to the Devonian. Shell form The shell is usually long, and may be straight ("orthoconic") or gently curved. In life, these animals may have been similar to the modern squid, except for the long shell. The internal structure of the shell consists of concavo-convex chambers linked by a centrally-placed tube called a siphuncle. There is a tendency for the chambers to develop cameral deposits, which were used as ballast to balance the long gas-filled shell. Depending on the family, the siphuncle has orthochoanitic (short and straight) or cyrtochoanitic (outwardly curved) septal necks, which protrude from the septa. The shell surface may be (depending on the specie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orthoceratoidea
Orthoceratoidea 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, Orthoceratiodea was one of six superorders within the Nautiloidea, the others being the Plectronoceratoidea (= Ellesm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orthoceratidae
Orthoceratidae is an extinct family of actively mobile carnivorous cephalopods, subclass Nautiloidea, that lived in what would be North America, Europe, Asia, Africa, and Australia from the Ordovician through Triassic from 490—203.7 mya, existing for approximately . Taxonomy Orthoceratidae was named by McCoy (1844) and assigned to the Orthocerida by Teichert and Miller (1939),(as Orthocerotidae);Sweet, Walter C., (1964), Nautiloidea --Orthocerida, in ''Treatise on Invertebrate Paleontology''. Part K. Mollusca 3. pp K224-K231. to the Michelinoceratida by Flower (1962),R. H. Flower. 1962. Memoir 10, Part 2; Notes on the Michelinoceratida. New Mexico Bureau of Mines and Mineral Resources, Socorro NM. and to the Orthocerataceae by Sweet (1964). It has been subsequently included in the Orthocerataceae in Evans (1994) and in the Orthocerida in Evans (2005) and in Kröger et al. (2007).B. Kröger, M. S. Beresi, and E. Landing. 2007. Early orthoceratoid cephalopods from the Argentine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geisonoceratidae
Geisonoceratidae is an extinct family of orthoceroid cephalopods endemic to what would be Asia, Europe, and North America from the Middle Ordovician to the Middle DevonianSweet, W. C. 1964. Nautiloidea- Orthocerida; Treatise on Invertebrate Paleontology Part K, Teichert & Moore eds; pp K224- K242 living from about 470—380 mya, existing for approximately 90 million years. With the possible addition of an Early Cretaceous orthocerid from the western Caucasus the range of this group increases dramatically to some 350 million years, thus making it one of the longest lived families of the Nautiloidea. Morphology Shells of geisonoceratids are orthoconic or cyrtoconic, that is long and either straight or curved, with a subcircular cross section. The siphuncle, which varies in position from central to subventral, is composed of generally short, straight to slightly curved, orthochoanitic to subchoanitic, septal necks and thin connecting rings that may expand slightly into the chambers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cephalopod
A cephalopod is any member of the molluscan class Cephalopoda (Greek plural , ; "head-feet") such as a squid, octopus, cuttlefish, or nautilus. These exclusively marine animals are characterized by bilateral body symmetry, a prominent head, and a set of arms or tentacles (muscular hydrostats) modified from the primitive molluscan foot. Fishers sometimes call cephalopods "inkfish", referring to their common ability to squirt 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 subclasses: Coleoidea, which includes octopuses, squid, and cuttlefish; and Nautiloidea, represented by ''Nautilus'' and ''Allonautilus''. In the Coleoidea, the molluscan shell has been internalized or is absent, whereas in the Nautiloidea, the external shell remains. About 800 living species of cephalopods have been ident ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Baltoceratidae
Baltoceratidae is an extinct family of orthoconic cephalopods belonging to the subclass Nautiloidea endemic to what would be Asia, Australia, Europe, North America, and South America during the Ordovician living from about 480–460 mya, existing for approximately . Taxonomy Baltoceratidae was named by Kobayashi (1935) and assigned to the Ellesmeroceratida by Flower and Kummel (1950) where it was retained by Unklesbay and Young (1956), again by Flower (1964)Flower 1964. The Nautiloid Order Ellesmeroceratida (Cephalopoda), Memoir 12, New Mexico Bureau of Mines and Mineral Resources, Socorro, NM , and by Furnish and Glenister in Teichert et al. (1964).Teichert et al 1964, Treatise on Invertebrate Paleontology Part K Mollusca 3, Nautiloidea-Ellesmerocerida by Furnish and Glenister, K129- K153 Flower (1964) included the Baltoceratidae in the ellesmeroceratid suborder Ellesmeroceratina. Further study of baltoceratid interiors, namely regarding the generally thin connecting r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paraphragmitidae
Paraphragmitidae is an extinct family of actively mobile aquatic carnivorous cephalopods belonging to the subclass Orthoceratoidea endemic to what would be Asia and Europe during the Silurian living from 436 to 418.7 mya, existing for approximately . In life, these animals may have been similar to the modern squid, except for the long shell. The internal structure of the shell consists of concavo-convex chambers linked by a centrally-placed tube called a siphuncle. Taxonomy The Paraphragmitidae was named and defined by Flower (1950) as containing annulated orthocones and cyrtocones included in the Michelinoceratida. Walter Sweet, (in Teichert ''et al'' 1964), included them in the Orthocerataceae, one of two superfamilies then of the Orthocerida (=Michelinocerida) . With the recognition of the Pseudorthocerida as a separate order the two superfamilies became obsolete leaving the Paraphragmitidae simply an orthocerid family . See also References *Flower (and Kümmel) 1950, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lamellorthoceratidae
Lamellorthoceratidae is a family of fossil orthoceratoids in the Orthocerida, defined by Curt Teichert in 1961. The lamellorthoceratids are placed in the superfamily Orthocerataceae in the ''Treatise on Invertebrate Paleontology'' (Walter Sweet, 1964). Lamellorthoceratids are distinguished by cameral deposits consisting of simple or bifurcating episeptal, or rarely hyposeptal lamellae, set radially with respect to the siphuncle; often filling the entire posterior part of the shell. Lamellorthoceratid shells are straight or slightly endogastric with a slender, cylindrical subcentral orthochoanitic siphuncle, free or organic deposits. The ''Lamellorthoceratidae'' are known from the Lower and Middle Devonian and possibly from the Lower Carboniferous, and is represented by three genera. Genera *''Lamellorthoceras'', a lamellorthoceriatid from the lower and middle Devonian of North Africa (Algeria, Morocco) characterized by radial lamellae that tend to be wavy, twisted, or to ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orthoceras
''Orthoceras'' ("straight horn") is a genus of extinct nautiloid cephalopod restricted to Middle Ordovician-aged marine limestones of the Baltic States and Sweden. This genus is sometimes called ''Orthoceratites''. Note it is sometimes misspelled as ''Orthocera'', ''Orthocerus'' or ''Orthoceros'' . ''Orthoceras'' was formerly thought to have had a worldwide distribution due to the genus' use as a wastebasket taxon for numerous species of conical-shelled nautiloids throughout the Paleozoic and Triassic. Since this work was carried out and re cataloging of the genus, ''Orthoceras'' sensu stricto refers to ''O. regulare'', of Ordovician-aged Baltic Sea limestones of Sweden and neighboring areas. These are slender, elongate shells with the middle of the body chamber transversely constricted, and a subcentral orthochoanitic siphuncle. The surface is ornamented by a network of fine lirae . Many other very similar species are included under the genus '' Michelinoceras''. History of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zhuravlevia
''Zhuravlevia'' is a genus of extinct shelled cephalopod that lived in the north west part of the Caucasus region of the middle east during the late Aptian stage of the early Cretaceous. This creature is believed to be an Orthocerid nautiloid, which if true would mean these cephalopods survived for over 90 million years longer then thought. This creature was found in the Hokodz river basin alongside other cephalopods like the Ammonites, Belemnities, and a phragmocone bearing coleoid called ''Naefia''. This cephalopod was assigned to the family Geisonoceratidae Geisonoceratidae is an extinct family of orthoceroid cephalopods endemic to what would be Asia, Europe, and North America from the Middle Ordovician to the Middle DevonianSweet, W. C. 1964. Nautiloidea- Orthocerida; Treatise on Invertebrate Pale ..., and was named after the describer of the family F. A. Zhuravleva, who also helped in the understanding of ancient cephalopods. References {{Taxonbar, from=Q113815371 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proteoceratidae
Proteoceratidae is an extinct family of actively mobile aquatic carnivorous cephalopods belonging to the subclass Orthoceratoidea endemic to what would be Asia, Australia, Europe, South America and North America during the Ordovician living from 490—445.6 Ma, existing for approximately . Taxonomy Proteoceratidae was named by Flower (1962). Its type is '' Proteoceras''. It was assigned to Michelinoceratida by Flower (1962); to Pseudorthocerataceae by Teichert et al. (1964), Sweet (1964) and Evans (1994); to Pseudorthocerida by Kröger and Isakar (2006); and to Orthocerida Orthocerida is an order of extinct Orthoceratoid cephalopods also known as the Michelinocerida that lived from the Early Ordovician () possibly to the Late Triassic (). A fossil found in the Caucasus suggests they may even have survived until ... by Kröger et al. (2007). B. Kröger, M. S. Beresi, and E. Landing. 2007. Early orthoceratoid cephalopods from the Argentine Precordillera (Lower-Middle O ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Engorthoceratidae
Engorthoceratidae is a small family of Devonian orthocerids and a class of cephalopod found in eastern North America (Ohio and Indiana), containing only the genus ''Engorthoceras''.R. H. Flower. (1962). "Notes on the Michelinoceratida". State Bureau of Mines and Mineral Resources, New Mexico Institute of Mining and Technology, Memoir 10, Part II PaleoBiology Database Taxonomy Engorthoceratidae was named in 1962 by to contain the genus ''Engorthoceras'', also named by Flower (1962), and assigned to the Michelinceratida. The |
Clinoceratidae
Clinoceratidae is an extinct family of actively mobile carnivorous cephalopod of the order Orthocerida that lived in what would be North America and Europe during the middle Ordovician through Early Silurian from 466–443.7 mya, existing for approximately . Taxonomy Clinoceratidae was named by Flower (1946). Its type is '' Clinoceras''. It was assigned to Michelinoceratida by Flower (1962).R. H. Flower. 1962. Part 1, Revision of Buttsoceras, Part 2, Notes on the Michelinoceratida. State Bureau of Mines and Mineral Resources, New Mexico Institute of Mining and Technology, Memoir 10:1-58 Morphology The shell is usually long, and may be straight ("orthoconic") or gently curved. In life, these animals may have been similar to the modern squid True squid are molluscs with an elongated soft body, large eyes, eight arms, and two tentacles in the superorder Decapodiformes, though many other molluscs within the broader Neocoleoidea are also called squid despite not strict ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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