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Liroceratidae
Liroceratidae is an extinct family of nautilids, shelled marine molluscs, belonging to the Clydonautiloidea, consisting of generally smooth, involute, nautiliconic forms with a small umbilicus. The whorl section is usually depressed and broadly rounded, the suture only slightly sinuous, and the siphuncle usually more or less central. The Liroceratidae range from the Mississippian well into the Triassic and may even extend down into the upper Devonian. The Liroceratidae are probably derived from the Rutoceratidae and form the root stock of the Clydonautiloidea. They also provide the basis for the name for Shimankiy's Lirocerina, a suborder mostly equivalent to the Clydonautilaceae. The Liroceratidae gave rise to the Ephippioceratidae early in the Mississippian, which extend well into the Permian, and to the Clydonautilidae, Gonionautilidae, and Siberionautilidae Siberionautilidae is a family in the nautilid superfamily Clydonautiloidea that contains only the genus ''Sibe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clydonautiloidea
The Clydonautiloidea are a superfamily within the nautiloid order Nautilida characterized by smooth, generally globular, shellsKummel 1964; Nautiloidea -Nautilida, Treatise on Invertebrate Paleontology, Part K Nautiliodea, Geological Society of America and University of Kansas press. with nearly straight sutures, in early forms, but developing highly differentiated sutures in some later forms. Where known, the siphuncle tends to be central to subcentral. The Clydonautiloidea, name based on Hyatt's Clydonautilidae of 1900, are more or less the Liroceratina of Shimansky 1962. Classification and taxonomy The Clydonautiloidea, which began in the Late Devonian, combine five families, three of which are restricted to the Triassic. Principal and forming the root stock are the Late Devonian to Upper Triassic Liroceratidae, from which Shimankiy derived his suborder. Derived from the Liroceratidae in the Early Mississippian are this Mississippian to mid Permian Ephippioceratidae. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ephippioceratidae
Ephippioceratidae is a family of clydonatilacean nautilids with shells as in the Liroceratidae but with sutures that have deep ventral and dorsal saddles. This group, which contains two genera, ''Ephippioceras'' and ''Megaglossoceras'', has a range from the Mississippian to the Lower Permian. ''Ephippioceras'', which has the full range of the family, has a broad, narrowly peaked ( V-shaped) ventral saddle and may have been derived from '' Liroceras'' early in the Mississippian. ''Megaglossoceras'' from the Pennsylvanian Pennsylvanian may refer to: * A person or thing from Pennsylvania * Pennsylvanian (geology) The Pennsylvanian ( , also known as Upper Carboniferous or Late Carboniferous) is, in the International Commission on Stratigraphy, ICS geologic timesca ... of North America, with its large, broadly arched, tongue-like ventral saddle is an obvious offshoot of ''Ephippioceras''. Both are subglobular and involute with a reniform whorl section. ''Ephippioceras'' has ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clydonautilidae
The Clydonautilidae are Middle and Upper Triassic nautiloid cephalopods, which are derivatives of the clydonautiloidean family Liroceratidae, that have generally smooth, involute, globular to compressed shells, characterized by a suture with prominent lobes and saddles. The family is known to contain five genera, These are: *''Clydonautilus ''Clydonautilus'' is a genus of nautiloids and type for the Clydonautilidae that has been found in the Upper Triassic of Europe, India, and Timor. Its type is ''C. noricus''. ''Clydonautilus'' is the most derived of the Clydonautilitidae, evide ...'' *'' Callaionautilus'' *'' Cosmonautilus'' *'' Proclydonautilus'' *'' Styrionautilus'' Of these only ''Styrionautilus'' is known from the Middle Triassic. The other four are so far restricted to the Upper Triassic. The five genera in the Clydonautilidae form a sequence of increasing sutural complexity, beginning with ''Styrionautilus'' and ending with ''Clydonautilus''. ''Styrionautili ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mississippian Age
The Mississippian ( , also known as Lower Carboniferous or Early Carboniferous) is a subperiod in the geologic timescale or a subsystem of the geologic record. It is the earlier of two subperiods of the Carboniferous period lasting from roughly 358.9 to 323.2 million years ago. As with most other geochronologic units, the rock beds that define the Mississippian are well identified, but the exact start and end dates are uncertain by a few million years. The Mississippian is so named because rocks with this age are exposed in the Mississippi Valley. The Mississippian was a period of marine transgression in the Northern Hemisphere: the sea level was so high that only the Fennoscandian Shield and the Laurentian Shield were dry land. The cratons were surrounded by extensive delta systems and lagoons, and carbonate sedimentation on the surrounding continental platforms, covered by shallow seas. In North America, where the interval consists primarily of marine limestones, it is treate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carboniferous
The Carboniferous ( ) is a geologic period and system of the Paleozoic that spans 60 million years from the end of the Devonian Period million years ago ( Mya), to the beginning of the Permian Period, million years ago. The name ''Carboniferous'' means "coal-bearing", from the Latin '' carbō'' ("coal") and '' ferō'' ("bear, carry"), and refers to the many coal beds formed globally during that time. The first of the modern 'system' names, it was coined by geologists William Conybeare and William Phillips in 1822, based on a study of the British rock succession. The Carboniferous is often treated in North America as two geological periods, the earlier Mississippian and the later Pennsylvanian. Terrestrial animal life was well established by the Carboniferous Period. Tetrapods (four limbed vertebrates), which had originated from lobe-finned fish during the preceding Devonian, became pentadactylous in and diversified during the Carboniferous, including early amphibian line ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triassic
The Triassic ( ) is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.36 Mya. The Triassic is the first and shortest period of the Mesozoic Era. Both the start and end of the period are marked by major extinction events. The Triassic Period is subdivided into three epochs: Early Triassic, Middle Triassic and Late Triassic. The Triassic began in the wake of the Permian–Triassic extinction event, which left the Earth's biosphere impoverished; it was well into the middle of the Triassic before life recovered its former diversity. Three categories of organisms can be distinguished in the Triassic record: survivors from the extinction event, new groups that flourished briefly, and other new groups that went on to dominate the Mesozoic Era. Reptiles, especially archosaurs, were the chief terrestrial vertebrates during this time. A specialized subgroup of archo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nautilida
The Nautilida constitute a large and diverse order of generally coiled nautiloid cephalopods that began in the mid Paleozoic and continues to the present with a single family, the Nautilidae which includes two genera, ''Nautilus'' and ''Allonautilus'', with six species. All told, between 22 and 34 families and 165 to 184 genera have been recognised, making this the largest order of the subclass Nautiloidea. Classification and phylogeny Current classification The current classification of the Nautilida, in prevalent use, is that of Bernhard Kummel (Kummel 1964) in the Treatise which divides the Nautilida into five superfamilies, the Aipocerataceae, Clydonautilaceae, Tainocerataceae, and Trigonocerataceae, mostly of the Paleozoic, and the later Nautilaceae. These include 22 families and some 165 or so genera (Teichert and Moore 1964) Other concepts Shimansky 1962 (in Kummel 1964) divided the Nautilida into five suborders, the mostly Paleozoic Centroceratina, Liroceratina, Rutoc ... [...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] |
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] |
Rutoceratidae
Rutoceratidae is a family of prototypical nautilids, derived probably from either Brevicoceratidae or Acleistoceratidae of the order Oncocerida early in the Devonian. Rutoceratidae comprise a family within the oncocerid superfamily TainocerataceaeKummel 1964, Nautiloidea-Nautilida; Treatise on Invertebrate Paleontology, Part K: Nautiloidea, Teichert & Moore (eds) They are generally characterized by cyrtoconic and gyroconic shells, commonly with spines, nodes, or frills, although some included genera are almost orthoconic, and a commonly empty, tubular ventral siphuncle. The Rutocertids lived during the Devonian and Mississippian (early Carboniferous) and are the ancestral stock of Nautilida. Within the superfamily Taintocerataceae, rutoceratids gave rise to the exclusively Devonian family Tetragonoceratidae and near the start of the Mississippian to the family Koninckioceratidae which lasted into the Permian and to Tainoceratidae which lasted through most of the Triassic. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gonionautilidae
Gonionautilidae is a family in the nautilid superfamily Clydonautiliaceae that contains only the genus ''Gonionautilus'', known from the Upper Triassic (Norian) of Europe and North America. (Alps, state of Nevada) ''Gonionautilus'' has a smooth, compressed involute shell with a narrow flattened venter and angular ventral shoulders. The suture resembles that of ''Clydonautilus'', from which it must have been derived, except for the more highly developed median saddle and bifurcated dorsal lobe. ''Gonionautilus'' (Gonionautilidae) is one of a number of advanced nautiloid cephalopods that developed sutures resembling those of some goniatites in the Ammonoidea Ammonoids are a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs, commonly referred to as ammonites, are more closely related to living coleoids (i.e., octopuses, squid and cuttle .... References * Bernhard Kummel, 1964. Nautiloidea -Nautilida; Treatise on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Siberionautilidae
Siberionautilidae is a family in the nautilid superfamily Clydonautiloidea that contains only the genus ''Siberionautilus'', which comes from the Upper Triassic ( Carnian) of Siberia, Russia. The family, and genus, are characterized by an involute, globular shell covered by fine radial ribs, with flattened flanks that converge toward a rounded venter, distinct umbilicus with rounded shoulders, differentiated suture, and central siphuncle. The suture is goniatitic with the ventral or median saddle of the Clydonautilidae, subdivided so as to have a deep finger-like median ventral lobe bracketed by finder-like secondary lobes and saddles, and on either side, a large claw-like asymmetric lateral lobe. Like '' Gonionautilus'', ''Siberionautilus'' is derived from the Clydonautilidae, only the genus is unspecified. As with ''Gonionautilus'' and more advanced Clydonautilidae, ''Siberionautilus'' is one of a handful of nautilids that have goniatitic sutures as found in primitive ammo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
