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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] |
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] |
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] |
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] |
Nautiloid
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 rel ... [...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] |
