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Procymatoceras
''Procymatoceras'' is a nautiloid cephalopod from the Middle Jurassic with a large, tightly involute, rapidly expanding shell. Early, inner, whorls are round in cross section. Later, outer, whorls, and mature living chamber are flattened on the sides and venter. Surface covered with sinuous ribs. Sutures have shallow ventral and dorsal lobes. Probably gave rise to '' Cymatonautilus'' and is the likely ancestor of '' Cymatoceras'' and '' Paracymatoceras''. ''Procymatoceras'' has its origin in the earliest Nautilidae, in ''Cenoceras ''Cenoceras'' is an extinct genus within the cephalopod mollusc family Nautilidae, which in turn makes up part of the superfamily Nautilaceae. This genus has been described by Hyatt in 1884. The type species is ''Cenoceras intermedium'' (Sowerb ...''. References *Bernhard Kümmel, 1964. Nautiloidea - Nautilida. Treatise on iInvertebrate Paleontology Part K. Geol. Soc. of America and Univ. Kans. Press, Teichert & Moore (eds) {{Taxonbar, from=Q72475 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jurassic
The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The Jurassic constitutes the middle period of the Mesozoic, Mesozoic Era and is named after the Jura Mountains, where limestone strata from the period were first identified. The start of the Jurassic was marked by the major Triassic–Jurassic extinction event, associated with the eruption of the Central Atlantic magmatic province, Central Atlantic Magmatic Province. The beginning of the Toarcian Stage started around 183 million years ago and is marked by an extinction event associated with widespread Anoxic event, oceanic anoxia, ocean acidification, and elevated temperatures likely caused by the eruption of the Karoo-Ferrar, Karoo-Ferrar large igneous provinces. The end of the Jurassic, however, has no clear boundary with the Cretaceous and i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cymatonautilus
''Cymatonautilus'' is a genus of cymatoceratids from the middle and upper Jurassic of Europe, the Middle East and Asia characterized by a robust shell with a wide umbilicus and subquadrate whorl section, slightly wider than high. The flanks and venter are flattened. The flanks have a wide lateral groove; the venter a more narrow median groove. The suture has a shallow ventral lobe and broad concave lateral lobes, crossed obliquely by sinuous ribs that produce a deep ventral sinus. The siphuncle is subcentral. References * Halder, K. and Bardhan, S. 1996. The fleeting genus ''Cymatonautilus'' (Nautiloidea): new record from the Jurassic Charl Formation, Kutch, India. Canadian Journal of Earth Sciences 33: 1007-1010. * Kummel, B. 1956. Post-Triassic nautiloid genera. Bulletin of the Museum of Comparative Zoology 114(7): 320-494. * Tintant, H. 1987. Les Nautiles du Jurassique d'Arabie Saoudite. Geobios 20: 67-159. {{Taxonbar, from=Q5199390 Prehistoric nautiloid genera Middle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cymatoceras
''Cymatoceras'' is a wide-ranging extinct genus from the nautilitacean cephalopod family, Cymatoceratidae. They lived from the Late Jurassic to Late Oligocene, roughly from 155 to 23 Ma.Sepkoski, JacSepkoski's Online Genus Database – Cephalopodes/ref> Species The following species of ''Cymatoceras'' have been described: * ''C. albense'' * ''C. atlas'' * ''C. bayfieldi'' * ''C. bifidum'' * ''C. bifurcatum'' * ''C. carlottense'' * ''C. cenomanense'' * ''C. colombiana'' * ''C. crebricostatum'' * ''C. deslongchampsianum'' * ''C. eichwaldi'' * ''C. elegans'' * ''C. hendersoni'' * ''C. hilli'' * ''C. honmai'' * ''C. hunstantonensis'' * ''C. huxleyanum'' * ''C. karakaschi'' * ''C. kayeanum'' * ''C. kossmati'' * ''C. loricatum'' * ''C. ludevigi'' * ''C. manuanensis'' * ''C. mikado'' * ''C. neckerianum'' * ''C. negama'' * ''C. neocomiense'' * ''C. pacificum'' * ''C. paralibanoticum'' * ''C. patagonicum'' * ''C. patens'' * ''C. perstriatum'' * ''C. picteti'' * '' C. pseudoatlas'' * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nautilidae
The nautilus (, ) is a pelagic marine mollusc of the cephalopod family Nautilidae. The nautilus is the sole extant family of the superfamily Nautilaceae and of its smaller but near equal suborder, Nautilina. It comprises six living species in two genera, the type genus, type of which is the genus ''Nautilus (genus), Nautilus''. Though it more specifically refers to species ''chambered nautilus, Nautilus pompilius'', the name chambered nautilus is also used for any of the Nautilidae. All are protected under CITES Appendix II. Depending on species, adult shell diameter is between 4 and 10 inches. Nautilidae, both extant and extinct, are characterized by involute or more or less convolute shells that are generally smooth, with compressed or depressed whorl (mollusc), whorl sections, straight to sinuous sutures, and a tubular, generally central siphuncle.Kümmel, B. 1964. Nautiloidae-Nautilida, in the Treatise on Invertebrate Paleontology, Geological Society of America and Univ of K ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cenoceras
''Cenoceras'' is an extinct genus within the cephalopod mollusc family Nautilidae, which in turn makes up part of the superfamily Nautilaceae. This genus has been described by Hyatt in 1884. The type species is ''Cenoceras intermedium'' (Sowerby). Species *'' Cenoceras boreale'' † Dagys and Sobolev 1988 *'' Cenoceras trechmanni'' † Kummel 1953 Description Shells of these nektonic carnivores are variable in form, depending on species; ranges from evolute to involute, compressed lenticular to globose with rounded to flattened venter and flanks. The suture generally has shallow ventral and lateral lobes. The location of the siphuncle is variable, but never at an extreme ventral or dorsal position (Kümmel 1964, K449). Fossil range ''Cenoceras'' has a fossil range from the Upper Triassic, Carnian age to the Middle Jurassic, Callovian In the geologic timescale, the Callovian is an age and stage in the Middle Jurassic, lasting between 166.1 ± 4.0 Ma (million years ago ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
