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Nassauoceras
''Nassauoceras'' is a tetragonoceratid nautiloid from the Middle Devonian of Europe, the shell of which is evolute with a wide, deep umbilicus, slight dorsal impression, low arched venter, rounded ventral shoulders, and flanks that converge dorsally so as to produce a subtrigonal whorl section. Nodes are present on the ventral shoulders. Sutures have shallow ventral and lateral lobes. The siphuncle is near the ventral margin. ''Nassauoceras'' differs from ''Tetragonoceras ''Tetragonoceras'' is an extinct prehistoric nautiloid genus from the nautilid family Tetragonoceratidae that lived during the Middle Devonian, found in Canada. ''Tetragonoceras'' has an openly spiralled, gyroconic shell with an almost square ...'' in that the latter is gyroconic with a subquadrate whorl section and angular ventral shoulders, but is somewhat similar to '' Wellsoceras'' in which whorls are in contact in the early growth stages and shoulders are also rounded. References *Bernhard Kumme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetragonoceratidae
The Tetragonoceratidae is a small family of nautilitids constituting a part of the superfamily Tainocerataceae in which shells are coiled with a generally quadrate whorl section. Coiling is either gyroconic or evoluute with a slight dorsal impression. Flanks diverge from the umbilical to the ventral shoulders so as to make the whorl sections widest close to the venter. Nodes made develop on the flanks and shoulders. The siphuncle is tubular, typically found near the venter. Sutures are with lateral lobes and may possess dorsal and ventral lobes as well. The Tetragonoceratidae, which is an early offshoot of the 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 Tainoceratac ..., contains three genera (as of 1964), all confined to the Middle Devonian: '' Tetragonoceras'', '' Nassauoce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Devonian
The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, where rocks from this period were first studied. The first significant adaptive radiation of life on dry land occurred during the Devonian. Free-sporing vascular plants began to spread across dry land, forming extensive forests which covered the continents. By the middle of the Devonian, several groups of plants had evolved leaves and true roots, and by the end of the period the first seed-bearing plants appeared. The arthropod groups of myriapods, arachnids and hexapods also became well-established early in this period, after starting their expansion to land at least from the Ordovician period. Fish reached substantial diversity during this time, leading the Devonian to often be dubbed the Age of Fishes. The placoderms began dominating ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Middle Devonian
The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, where rocks from this period were first studied. The first significant adaptive radiation of life on dry land occurred during the Devonian. Free-sporing vascular plants began to spread across dry land, forming extensive forests which covered the continents. By the middle of the Devonian, several groups of plants had evolved leaves and true roots, and by the end of the period the first seed-bearing plants appeared. The arthropod groups of myriapods, arachnids and hexapods also became well-established early in this period, after starting their expansion to land at least from the Ordovician period. Fish reached substantial diversity during this time, leading the Devonian to often be dubbed the Age of Fishes. The placoderms began dominating al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Europe
Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia and it is located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. Comprising the westernmost peninsulas of Eurasia, it shares the continental landmass of Afro-Eurasia with both Africa and Asia. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south and Asia to the east. Europe is commonly considered to be Boundaries between the continents of Earth#Asia and Europe, separated from Asia by the drainage divide, watershed of the Ural Mountains, the Ural (river), Ural River, the Caspian Sea, the Greater Caucasus, the Black Sea and the waterways of the Turkish Straits. "Europe" (pp. 68–69); "Asia" (pp. 90–91): "A commonly accepted division between Asia and E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetragonoceras
''Tetragonoceras'' is an extinct prehistoric nautiloid genus from the nautilid family Tetragonoceratidae that lived during the Middle Devonian, found in Canada. ''Tetragonoceras'' has an openly spiralled, gyroconic shell with an almost square cross section, but with the venter on the outer rim broader than the dorsum on the inner. The sides are flattish and converge slightly on the dorsum and the ventro-lateral shoulders are angular. The suture of ''Tetragonoceras'' has slight lateral and ventral lobes separated by subangular saddles. The siphuncle is ventral and tubular. ( 1964.). A member of the Tetragonoceratidae, ''Tetragonoceras'' is also a component of the superfamily Tainocerataceae. References * , B. 1964. Nautiloidea-Nautilida ''in the'' Treatise on Invertebrate Paleontology The ''Treatise on Invertebrate Paleontology'' (or ''TIP'') published by the Geological Society of America and the University of Kansas Press, is a definitive multi-authored work of some 50 v ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wellsoceras
''Wellsoceras'' is a tetragonoceratid that starts off with an evolute shell in which whorls are in contact, but has a mature living chamber that diverges and becomes free. The whorl section is slightly wider than high and is faintly subquadrangular. Flanks are slightly convex and tend to converge very slightly toward the center. All shoulders are strongly rounded. The suture is straight ventrally or with a slight ventral lobe, well developed lateral lobes, and a broad, low dorsal saddle. The siphuncle is located half way between the center and the ventral margin. ''Wellsoceras'' has been found in Middle Devonian sediments in eastern North America, in Ohio, Indiana, and Ontario. References * Bernhard Kummel, 1964. Nautiloidea-Nautilida; Treatise on Invertebrate Paleontology, Part L; Geological Society of America; R.C. Moore & Curt Teichert, (eds). Nautiloids Taxa named by Rousseau H. Flower {{paleo-cephalopod-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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