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Callaionautilus
''Callaionautilus'' is a genus of cephalopods included in the nautilid family Clydonautilidae that lived during the Late Triassic. Its fossils have been found on the island of Timor. The shell of ''Callaionautilus'' is involute, coiled such that only the outer whorl is exposed. Early whorls have nodes on the ventral shoulder that disappear toward the aperture. Later whorls have a nodose keel bordered by furrows. The siphuncle position is unknown. ''Clydonautilus'', ''Cosmonautilus ''Cosmonautilus'' is a genus of cephalopods included in the nautilid family Clydonautilidae. Its shell is involute, with only the outer whorl exposed. Early whorls are with nodes on ventral shoulder, which disappear on the later growth staged. ...'', '' Proclydonautilus'', and '' Styrionautilus'' are closely related genera belonging to the same family. References * Bernhard Kummel, 1964. Nautiloidea-Nautilida. Treatise on Invertebrate Paleontology, Part K. Geological Society of America. ''Calla ... [...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] |
Cosmonautilus
''Cosmonautilus'' is a genus of cephalopods included in the nautilid family Clydonautilidae. Its shell is involute, with only the outer whorl exposed. Early whorls are with nodes on ventral shoulder, which disappear on the later growth staged. Later whorls are smooth. ''Cosmonautilus'' has been found in Siberian Russia, e.g. in eastern Taimyr and in the lower Lena River region, and in Alaska on Gravina Island, and California from Shasta County in the US, as well as Mexico, India, and Timor. '' Callaionautilus'' and ''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 ...'' are among related genera included in the Clydonautilidae. References * Bernhard Kummel, 1964. Nautiloidea-Nautilida. Treatise on Invertebrate Paleontology, Part K. Geological Society of America. '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proclydonautilus
''Proclydonautilus'' is a genus of nautiloids belonging to the Clydonautilidae known from the Upper Triassic of North America, Europe, and India. The shell of ''Proclydonautilus'', like those of other Clydonautilitidae, is involute and smooth. It is distinguished by its suture which has a broad, shallow to deep ventral lobe that divides a large ventral saddle. A large lateral lobe on the flans is followed by a small lateral saddle and a second lateral lobe. With regard to the suture ''Proclydonautilus'' is most similar to ''Cosmonautilus'' and ''Callaionautilus ''Callaionautilus'' is a genus of cephalopods included in the nautilid family Clydonautilidae that lived during the Late Triassic. Its fossils have been found on the island of Timor. The shell of ''Callaionautilus'' is involute, coiled such tha ...'', both also from the Late Triassic. References * Berhard Kummel, 1964. Nautiloidea-Nautilida. Treatise on Invertebrate Paleontology, Part K. Geological Society of Ameri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Styrionautilus
''Styrionautilus'' is a genus of nautiloids and first of the Clydonautilidae with a range extending from the Middle Triassic, Anisian to the Upper Triassic, Norian. Its fossils have been found in North America (Nevada), Europe, and Timor. In general form ''Styrionautilus'' is similar to other clydonautilids, smooth and involute. The suture however is more primitive. The ventral saddle is straight across without modification of a median lobe. ''Styrionautilus'' may be derived from '' Indionautilus'' or similar form included in the Liroceratidae. In turn ''Styrionautilus'' is the likely ancestor of ''Proclydonautilus'', ''Cosmonautilus'', and/or ''Callaionautilus ''Callaionautilus'' is a genus of cephalopods included in the nautilid family Clydonautilidae that lived during the Late Triassic. Its fossils have been found on the island of Timor. The shell of ''Callaionautilus'' is involute, coiled such tha ...'' References * Bernhard Kummel, 1964. Nautiloidea-Nautilida. Treati ... [...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] |
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, evidenced in its suture. The shell itself is smooth and involute, with only the outer whorl exposed. The diagnostic suture has a small median saddle in the ventral lobe which in turn has a smaller shallow lobe. Those in other clydonautilitids are less complex. References * Bernhard Kummel, 1964. Nautiloidea -Natilida. Treatise on Invertebrate Paleontology, Part K. Geological Society of America and University of Kansas Press. Prehistoric nautiloid genera {{paleo-nautiloidea-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
