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Cyrthoceratites
''Cyrthoceratites'' is an extinct genus of prehistoric nautiloids. The nautiloids are a subclass of shelled cephalopods that were once diverse and numerous but are now represented by only a handful of species. See also * Nautiloid ** List of nautiloids This list of nautiloids is a comprehensive listing of all genera that have ever been included in the subclass Nautiloidea, excluding purely vernacular terms. The list includes all commonly accepted genera, but also genera that are now considered in ... References * Sepkoski, J.J. Jr. 2002. A compendium of fossil marine animal genera. D.J. Jablonski & M.L. Foote (eds.). ''Bulletins of American Paleontology'' 363: 1–560Sepkoski's Online Genus Database (CEPHALOPODA) Prehistoric nautiloid genera {{paleo-nautiloid-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Nautiloids
This list of nautiloids is a comprehensive listing of all genera that have ever been included in the subclass Nautiloidea, excluding purely vernacular terms. The list includes all commonly accepted genera, but also genera that are now considered invalid, doubtful (''nomina dubia''), or were not formally published (''nomina nuda''), as well as junior synonyms of more established names, and genera that are no longer considered nautiloids. Most of the listed genera are found in Part K of the ''Treatise on Invertebrate Paleontology''. Some, added since the year of publication (1964) are found simply in various scientific journals and special publications. The named genera are based on type specimens which are housed in various museums and other academic institutions worldwide, available to interested researchers. Note that ''Allonautilus'' and ''Nautilus'' are the only extant genera. A *†'' Acanthonautilus'' *†'' Acaroceras'' *†'' Acleistoceras'' *†'' Acrosphaerorthoceras' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extinct
Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point. Because a species' potential range may be very large, determining this moment is difficult, and is usually done retrospectively. This difficulty leads to phenomena such as Lazarus taxa, where a species presumed extinct abruptly "reappears" (typically in the fossil record) after a period of apparent absence. More than 99% of all species that ever lived on Earth, amounting to over five billion species, are estimated to have died out. It is estimated that there are currently around 8.7 million species of eukaryote globally, and possibly many times more if microorganisms, like bacteria, are included. Notable extinct animal species include non-avian dinosaurs, saber-toothed cats, dodos, m ... [...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] |
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