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Grypoceratidae
Grypoceratidae is the longest-lived family of the Trigonoceratoidea, or of the near equivalent Centroceratina; members of the Nautilida from the Upper Paleozoic and Triassic.Kummel,B. 1964. Nautiloidea-Nautilida, Treatise on Invertebrate Paleontology Part K, Teichert and Moore (eds) Geological Society of America and University of Kansas Press. Diagnosis The Grypoceratidae are characterized by evolute to involute shells that may have some modification to the venter (the outer rim) varying from flattened to subangular, or bearing a keel. Most are smooth but some have nodes or carinae (auxiliary keels). Sutures generally have distinct ventral and lateral lobes but in some, a ventral saddle. Whorl sections are generally compressed but may be subquadrate to subtrapezoidal or coronate (heart shaped), or slightly depressed dorso-ventrally.Flower 1950;Flower and Kummel, A Classification of the Nautiloidea, Journal of Paleontology Vol 24, no.5, pp 604–616, Sept 1950. Phylogeny and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Centroceratina
The Trigonoceratoidea are a superfamily within the Nautilida that ranged from the Devonian to the Triassic, thought to have contained the source for the Nautilaceae in which ''Nautilus'' is found. Trigonoceratoidea are characterized by open-spiraled, gyroconic, to closed, nautiliconic shells in which the Whorl section is quadrate in primitive forms; the venter typically narrow to acute, the dorsum broad. In some advanced forms, the venter may become concave or broad and rounded, and in some, the surfaces may be strongly lirate. Classification and phylogeny The Trigonoceratoidea are based on the family Trigonoceratidae of Alpheus Hyatt, 1884, with which other phylogenetically related families are combined, and are equivalent to the abandoned Centroceratida of Flower in Flower and Kümmel 1950, and to the Centroceratina of Shimanskiy 1957, revised to the Centrocerataceae, Shimanskiy 1962. The Trigonoceratoidea combine five families, the type, Trigonoceratidae, along with the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trigonoceratoidea
The Trigonoceratoidea are a superfamily within the Nautilida that ranged from the Devonian to the Triassic, thought to have contained the source for the Nautilaceae in which '' Nautilus'' is found. Trigonoceratoidea are characterized by open-spiraled, gyroconic, to closed, nautiliconic shells in which the Whorl section is quadrate in primitive forms; the venter typically narrow to acute, the dorsum broad. In some advanced forms, the venter may become concave or broad and rounded, and in some, the surfaces may be strongly lirate. Classification and phylogeny The Trigonoceratoidea are based on the family Trigonoceratidae of Alpheus Hyatt, 1884, with which other phylogenetically related families are combined, and are equivalent to the abandoned Centroceratida of Flower in Flower and Kümmel 1950, and to the Centroceratina of Shimanskiy 1957, revised to the Centrocerataceae, Shimanskiy 1962. The Trigonoceratoidea combine five families, the type, Trigonoceratidae, along with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Titanoceras
''Titanoceras'' is an extinct genus in the nautiloid order Nautilida from the Pennsylvanian and Lower Permian of North America and Western Australia. ''Titanoceras'' grew to be fairly large, with a tightly spiraled shell that reached a diameter of about 8 in (20 cm +) with about three volutions. The inner coils are partially enveloped by the next outer, resulting in a channel or impression along the inner rim, the dorsum. Otherwise all whorls are visible. (The descriptive term is evolute). Whorls have a somewhat rectangular cross section that is wider than high; in contrast with the otherwise similar and contemporary ''Domatoceras''. The venter, which forms the outer rim, may be broadly arched. Septa are close spaced making chambers broad but short. Sutures have shallow lobes along the sides and across the venter and short saddles in between, along the ventro-lateral shoulders, but go straight across the dorsum. ''Titanoceras'' is found is limestone, indicating it live ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gryponautilus
''Gryponautilus'' is a genus of Upper Triassic nautilids (''generally coiled nautiloid cephalopods'') belonging to the trigonoceratacean family Grypoceratidae, characterized by involute, inflated shells, which at maturity develop narrowly rounded keel-like venters. Venters on inner whorls are truncated and broadly convex to concave. Immature forms bear a resemblance to ''Grypoceras ''Grypoceras'' is a coiled nautiloid cephalopod from the Triassic of western North America, southern Asia, and Europe that belongs to the nautilid family Grypoceratidae. Named by Alpheus Hyatt Alpheus Hyatt (April 5, 1838 – January ...''. References * Prehistoric nautiloid genera {{paleo-nautiloidea-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Domatoceras Umbilicatum
''Domatoceras'' is a nautiloid genus and member of the Grypoceratidae from the Pennsylvanian and Permian with a wide spread distribution. The shell of ''Domatoceras'' is evolute, coiled with whorls touching but not overlapping, some growing to be moderately large. Whorl section subquadrate, higher than wide. Sides essentially straight to slightly bowed and slightly convergent on a broad slightly arched venter on the outer rim. Shoulder are narrow but rounded. Chambers are short but lengthen slightly before the mature living chamber, septa close spaced, sutures form broad shallow lateral and ventral lobes and sharp ventro-lateral saddles. The dorsum in slightly impressed (indented) where it rides over the previous whorl. The 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grypoceras
''Grypoceras'' is a coiled nautiloid cephalopod from the Triassic of western North America, southern Asia, and Europe that belongs to the nautilid family Grypoceratidae. Named by Alpheus Hyatt in 1883, the shell of ''Grypoceras'' is essentially involute with a subtriangular cross section, widest across the umbilical shoulders, with flanks fairing toward a narrow flattened venter. Sutures on flanks are with smooth, deep lobes and with shallow ventral lobes. The earlier, related ''Domatoceras'' is evolute, with a more quadrate whorl section. ''Gryponautilus ''Gryponautilus'' is a genus of Upper Triassic nautilids (''generally coiled nautiloid cephalopods'') belonging to the trigonoceratacean family Grypoceratidae, characterized by involute, inflated shells, which at maturity develop narrowly round ...'', from the Upper Triassic, is more strongly involute and has a sharply keeled venter. References * Bernhard Kummel, 1964, Nautiloidea-Nautilida. Treatise on Invertebrate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Domatoceras
''Domatoceras'' is a nautiloid genus and member of the Grypoceratidae from the Pennsylvanian and Permian with a wide spread distribution. The shell of ''Domatoceras'' is evolute, coiled with whorls touching but not overlapping, some growing to be moderately large. Whorl section subquadrate, higher than wide. Sides essentially straight to slightly bowed and slightly convergent on a broad slightly arched venter on the outer rim. Shoulder are narrow but rounded. Chambers are short but lengthen slightly before the mature living chamber, septa close spaced, sutures form broad shallow lateral and ventral lobes and sharp ventro-lateral saddles. The dorsum in slightly impressed (indented) where it rides over the previous whorl. The 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleozoic
The Paleozoic (or Palaeozoic) Era is the earliest of three geologic eras of the Phanerozoic Eon. The name ''Paleozoic'' ( ;) was coined by the British geologist Adam Sedgwick in 1838 by combining the Greek words ''palaiós'' (, "old") and ''zōḗ'' (), "life", meaning "ancient life" ). It is the longest of the Phanerozoic eras, lasting from , and is subdivided into six geologic periods (from oldest to youngest): # Cambrian # Ordovician # Silurian # Devonian # Carboniferous # Permian The Paleozoic comes after the Neoproterozoic Era of the Proterozoic Eon and is followed by the Mesozoic Era. The Paleozoic was a time of dramatic geological, climatic, and evolutionary change. The Cambrian witnessed the most rapid and widespread diversification of life in Earth's history, known as the Cambrian explosion, in which most modern phyla first appeared. Arthropods, molluscs, fish, amphibians, reptiles, and synapsids all evolved during the Paleozoic. Life began in the ocean bu ... [...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, Ru ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Family (taxonomy)
Family ( la, familia, plural ') is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between order and genus. A family may be divided into subfamilies, which are intermediate ranks between the ranks of family and genus. The official family names are Latin in origin; however, popular names are often used: for example, walnut trees and hickory trees belong to the family Juglandaceae, but that family is commonly referred to as the "walnut family". What belongs to a family—or if a described family should be recognized at all—are proposed and determined by practicing taxonomists. There are no hard rules for describing or recognizing a family, but in plants, they can be characterized on the basis of both vegetative and reproductive features of plant species. Taxonomists often take different positions about descriptions, and there may be no broad consensus across the scientific community for some time. The publishing of new data and opinion ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
