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Cymatoceratidae
The Cymatoceratidae is a family of Mesozoic and early Cenozoic nautiloid cephalopods and the most abundant of this kind in the Cretaceous. They are characterized by ribbed, generally involute shells of varied form - coiled such that the outer whorl envelops the previous, as with Nautilus, and sutures that are variably sinuous.Kummel 1964. Nautiloidea-Nautilida; Treatise on Invertebrate Paleontology Part K; Teichert and Moore (eds), Geological Society of America and University of Kansas press Cymatoceratids first appear in the Middle Jurassic, derived from the Lower Jurassic ''Cenoceras'' ( Nautilidae) and extend as far as the Oligocene. Taxonomy Ten cymatoceratid genera are described in the Treatise Part K, 1964. First to appear was the large, tightly involute, rapidly expanding '' Procymatoceras'' from the Middle Jurassic, followed by the Middle and Upper Jurassic '' Cymatonautilus'' which has a wide umbilicus and subquadrate whorl section. ''Procymatoceras'' and ''Cymatonau ... [...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] |
Deltocymatoceras
''Deltocymatoceras'' is an involute cymatoceratid (Nautilioidea-Nautilida) with broadly arched whorl sides, strongly convergent on a narrow venter that bears a slight, rounded, keel-like ridge, and with no distinct ventro-latera shoulders. Sides bear cymatoceratid ribs that bifurcate near the middle of the whorl sides, but do not cross the venter. The suture has a somewhat pointed ventral saddle, broad lateral lobes (one on each side) and prominent saddles on the umbilical shoulders (again, one per side). The position of the siphuncle in undetermined. ''Deltocymatoceras'' is probably derived form '' Cymatoceras'' by a rounding of the ventro-lateral shoulders resulting in a narrowing of the venter, coupled with the development of a pointed ventral saddle. '' Eucymatoceras'' from the Lower Cretaceous is similar, except for lacking the vernal keel. Contemporary, Upper Cretaceous '' Epicymatoceras'' is involute, discoidal. '' Deltoidonautiluds'' with its similar name, and converging ... [...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 Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an ... 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. 19 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cenozoic Cephalopods
The Cenozoic ( ; ) is Earth's current geological era, representing the last 66million years of Earth's history. It is characterised by the dominance of mammals, birds and flowering plants, a cooling and drying climate, and the current configuration of continents. It is the latest of three geological eras since complex life evolved, preceded by the Mesozoic and Paleozoic. It started with the Cretaceous–Paleogene extinction event, when many species, including the non-avian dinosaurs, became extinct in an event attributed by most experts to the impact of a large asteroid or other celestial body, the Chicxulub impactor. The Cenozoic is also known as the Age of Mammals because the terrestrial animals that dominated both hemispheres were mammalsthe eutherians (placentals) in the northern hemisphere and the metatherians (marsupials, now mainly restricted to Australia) in the southern hemisphere. The extinction of many groups allowed mammals and birds to greatly diversify so that larg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesozoic Cephalopods
The Mesozoic Era ( ), also called the Age of Reptiles, the Age of Conifers, and colloquially as the Age of the Dinosaurs is the second-to-last era of Earth's geological history, lasting from about , comprising the Triassic, Jurassic and Cretaceous Periods. It is characterized by the dominance of archosaurian reptiles, like the dinosaurs; an abundance of conifers and ferns; a hot greenhouse climate; and the tectonic break-up of Pangaea. The Mesozoic is the middle of the three eras since complex life evolved: the Paleozoic, the Mesozoic, and the Cenozoic. The era began in the wake of the Permian–Triassic extinction event, the largest well-documented mass extinction in Earth's history, and ended with the Cretaceous–Paleogene extinction event, another mass extinction whose victims included the non-avian dinosaurs, pterosaurs, mosasaurs, and plesiosaurs. The Mesozoic was a time of significant tectonic, climatic, and evolutionary activity. The era witnessed the gradual rifti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prehistoric Nautiloid Families
Prehistory, also known as pre-literary history, is the period of human history between the use of the first stone tools by hominins 3.3 million years ago and the beginning of recorded history with the invention of writing systems. The use of symbols, marks, and images appears very early among humans, but the earliest known writing systems appeared 5000 years ago. It took thousands of years for writing systems to be widely adopted, with writing spreading to almost all cultures by the 19th century. The end of prehistory therefore came at very different times in different places, and the term is less often used in discussing societies where prehistory ended relatively recently. In the early Bronze Age, Sumer in Mesopotamia, the Indus Valley Civilisation, and ancient Egypt were the first civilizations to develop their own scripts and to keep historical records, with their neighbors following. Most other civilizations reached the end of prehistory during the following Iron Age. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heminautilus
''Heminautilus'' is an extinct genus of nautiloids from the nautilacean family Cenoceratidae that lived during the Early Cretaceous. Fossils of ''Heminautilus'' have been registered in rocks of Barremian and Aptian age.''Heminautilus'' at .org are a subclass of shelled that were once diverse and numerous but are now represented by only a handful of species. ''Heminautilus'' has a discoidal compressed involute ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of the entire Phanerozoic. The name is derived from the Latin ''creta'', " chalk", which is abundant in the latter half of the period. It is usually abbreviated K, for its German translation ''Kreide''. The Cretaceous was a period with a relatively warm climate, resulting in high eustatic sea levels that created numerous shallow inland seas. These oceans and seas were populated with now-extinct marine reptiles, ammonites, and rudists, while dinosaurs continued to dominate on land. The world was ice free, and forests extended to the poles. During this time, new groups of mammals and birds appeared. During the Early Cretaceous, flowering plants appeared and began to rapidly diversify, becoming the dominant group of plants across the Ear ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
