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Clarkeiteuthis
''Clarkeiteuthis'' is a genus of extinct belemnoid cephalopod known from the lower Jurassic in Germany and England. Described two species, ''C. conocauda'' and ''C. montefiorei'' are originally described as species of phragmoteuthid ''Phragmoteuthis'', but got their own genus and moved to Diplobelida. Description Two species are described, ''C. conocauda'' is known from Posidonia Shale, and ''C. montefiorei'' is known from Charmouth Mudstone Formation. ''Clarkeiteuthis'' had long phragmocone and ten short, hook-bearing arms. Although it is originally considered as phragmoteuthid, this classification has been discussed by modern researchers, as it lacked a broad three-lobed proostracum (The anterior prolongation of the guard of the phragmocone), the autapomorphy of phragmoteuthid. ''C. conocauda'' had total length about . This species is well preserved, soft tissues such as mantle and ink sac are visible. One arm had around 30 hooks. Palaeobiology Well-preserved speci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clarkeiteuthis And Leptolepis Reconstruction
''Clarkeiteuthis'' is a genus of extinct belemnoid cephalopod known from the lower Jurassic in Germany and England. Described two species, ''C. conocauda'' and ''C. montefiorei'' are originally described as species of phragmoteuthid ''Phragmoteuthis'', but got their own genus and moved to Diplobelida. Description Two species are described, ''C. conocauda'' is known from Posidonia Shale, and ''C. montefiorei'' is known from Charmouth Mudstone Formation. ''Clarkeiteuthis'' had long phragmocone and ten short, hook-bearing arms. Although it is originally considered as phragmoteuthid, this classification has been discussed by modern researchers, as it lacked a broad three-lobed proostracum (The anterior prolongation of the guard of the phragmocone), the autapomorphy of phragmoteuthid. ''C. conocauda'' had total length about . This species is well preserved, soft tissues such as mantle and ink sac are visible. One arm had around 30 hooks. Palaeobiology Well-preserved specime ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leptolepis
''Leptolepis'' (from el, λεπτός , 'slight' and el, λεπίς 'scale') is an extinct genus of stem-teleost fish that lived in what is now Europe during the Jurassic period (Toarcian–Callovian ages). Species The genus ''Leptolepis'' was for a long time used as a wastebasket taxon for various small, unspecialised teleosts that did not form a natural clade. In 1974 the Swedish ichthyologist Orvar Nybelin revised the genus, restricting it to seven species from the Early to Middle Jurassic of Europe. Other species were reassigned to different genera. * ''Leptolepis autissiodorensis'' * ''Leptolepis coryphaenoides'' * ''Leptolepis jaegeri'' * ''Leptolepis nathorsti'' * ''Leptolepis normandica'' * ''Leptolepis saltviciensis'' * ''Leptolepis woodwardi'' Species formerly placed in ''Leptolepis'' * ''Leptolepis talbragarensis'' (Now referred to ''Cavenderichthys'') * ''Leptolepis koonwarri'' (Now referred to '' Waldmanichthys'')Sferco, Emilia, Adriana López-Arb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Belemnoidea
Belemnoids are an extinct group of marine cephalopod, very similar in many ways to the modern squid and closely related to the modern cuttlefish. Like them, the belemnoids possessed an ink sac, but, unlike the squid, they possessed ten arms of roughly equal length, and no tentacles. The name "belemnoid" comes from the Greek word βέλεμνον, ''belemnon'' meaning "a dart or arrow" and the Greek word είδος, ''eidos'' meaning "form". Belemnoids include belemnites (which belong to order Belemnitida proper), aulacocerids (order Aulacocerida), phragmoteuthids (order Phragmoteuthida), and diplobelids (order Diplobelida). Occurrence Belemnoids were numerous during the Jurassic and Cretaceous periods, and their fossils are abundant in Mesozoic marine rocks, often accompanying their cousins the ammonites. The belemnoids become extinct at the end of the Cretaceous period along with the ammonites. The belemnoids' origin lies within the bactritoid nautiloids, which date fro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cephalopod
A cephalopod is any member of the molluscan class Cephalopoda (Greek plural , ; "head-feet") such as a squid, octopus, cuttlefish, or nautilus. These exclusively marine animals are characterized by bilateral body symmetry, a prominent head, and a set of arms or tentacles (muscular hydrostats) modified from the primitive molluscan foot. Fishers sometimes call cephalopods "inkfish", referring to their common ability to squirt ink. The study of cephalopods is a branch of malacology known as teuthology. Cephalopods became dominant during the Ordovician period, represented by primitive nautiloids. The class now contains two, only distantly related, extant subclasses: Coleoidea, which includes octopuses, squid, and cuttlefish; and Nautiloidea, represented by ''Nautilus'' and ''Allonautilus''. In the Coleoidea, the molluscan shell has been internalized or is absent, whereas in the Nautiloidea, the external shell remains. About 800 living species of cephalopods have been ident ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phragmoteuthis
''Phragmoteuthis'' is a genus of extinct coleoid cephalopod known from the late Triassic to the lower Jurassic. Its soft tissue has been preserved; some specimens contain intact ink sacs, and others, gills. It had an internal phragmocone and unknown numbers of arms. Previously described species, ''P. conocauda'' and ''P. montefiorei'' got their own genus, ''Clarkeiteuthis ''Clarkeiteuthis'' is a genus of extinct belemnoid cephalopod known from the lower Jurassic in Germany and England. Described two species, ''C. conocauda'' and ''C. montefiorei'' are originally described as species of phragmoteuthid '' Phragmot ...''. References Belemnoidea Jurassic cephalopods Triassic cephalopods Mesozoic cephalopods of Europe Prehistoric life of Europe Late Triassic first appearances Early Jurassic extinctions Prehistoric cephalopod genera {{paleo-cephalopod-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phragmoteuthis Conocauda
''Phragmoteuthis'' is a genus of extinct coleoid cephalopod known from the late Triassic to the lower Jurassic. Its soft tissue has been preserved; some specimens contain intact ink sacs, and others, gills. It had an internal phragmocone and unknown numbers of arms. Previously described species, ''P. conocauda'' and ''P. montefiorei'' got their own genus, ''Clarkeiteuthis ''Clarkeiteuthis'' is a genus of extinct belemnoid cephalopod known from the lower Jurassic in Germany and England. Described two species, ''C. conocauda'' and ''C. montefiorei'' are originally described as species of phragmoteuthid ''Phragmot ...''. References Belemnoidea Jurassic cephalopods Triassic cephalopods Mesozoic cephalopods of Europe Prehistoric life of Europe Late Triassic first appearances Early Jurassic extinctions Prehistoric cephalopod genera {{paleo-cephalopod-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sinemurian
In the geologic timescale, the Sinemurian is an age and stage in the Early or Lower Jurassic Epoch or Series. It spans the time between 199.3 ± 2 Ma and 190.8 ± 1.5 Ma (million years ago). The Sinemurian is preceded by the Hettangian and is followed by the Pliensbachian. In Europe the Sinemurian age, together with the Hettangian age, saw the deposition of the lower Lias, in Great Britain known as the Blue Lias. Stratigraphic definitions The Sinemurian Stage was defined and introduced into scientific literature by French palaeontologist Alcide d'Orbigny in 1842. It takes its name from the French town of Semur-en-Auxois, near Dijon. The calcareous soil formed from the Jurassic limestone of the region is in part responsible for the character of the classic Sancerre wines. The base of the Sinemurian Stage is at the first appearance of the ammonite genera ''Vermiceras'' and '' Metophioceras'' in the stratigraphic record. A global reference profile ( GSSP or golden spike) for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cephalopod Limb
All cephalopods possess flexible limbs extending from their heads and surrounding their beaks. These appendages, which function as muscular hydrostats, have been variously termed arms, legs or tentacles. Description In the scientific literature, a cephalopod ''arm'' is often treated as distinct from a ''tentacle'', though the terms are sometimes used interchangeably, often with the latter acting as an umbrella term for cephalopod limbs. Generally, arms have suckers along most of their length, as opposed to tentacles, which have suckers only near their ends.Young, R.E., M. Vecchione & K.M. Mangold 1999Cephalopoda Glossary Tree of Life web project. Barring a few exceptions, octopuses have eight arms and no tentacles, while squid and cuttlefish have eight arms (or two "legs" and six "arms") and two tentacles.Norman, M. 2000. ''Cephalopods: A World Guide''. ConchBooks, Hackenheim. p. 15. "There is some confusion around the terms ''arms'' versus ''tentacles''. The numerous lim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prehistoric Life Of Europe
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. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesozoic Cephalopods Of Europe
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 rifting ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jurassic Cephalopods
The Jurassic ( ) is a geologic period and 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 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. The beginning of the Toarcian Stage started around 183 million years ago and is marked by an extinction event associated with widespread oceanic anoxia, ocean acidification, and elevated temperatures likely caused by the eruption of the Karoo-Ferrar large igneous provinces. The end of the Jurassic, however, has no clear boundary with the Cretaceous and is the only boundary between geological periods to remain formally undefined. By the beginning of the Jurassic, t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Belemnitida
Belemnitida (or the belemnite) is an extinct order of squid-like cephalopods that existed from the Late Triassic to Late Cretaceous. Unlike squid, belemnites had an internal skeleton that made up the cone. The parts are, from the arms-most to the tip: the tongue-shaped pro-ostracum, the conical phragmocone, and the pointy guard. The calcitic guard is the most common belemnite remain. Belemnites, in life, are thought to have had 10 hooked arms and a pair of fins on the guard. The chitinous hooks were usually no bigger than , though a belemnite could have had between 100 and 800 hooks in total, using them to stab and hold onto prey. Belemnites were an important food source for many Mesozoic marine creatures, both the adults and the planktonic juveniles, and likely played an important role in restructuring marine ecosystems after the Triassic–Jurassic extinction event. They may have laid between 100 and 1,000 eggs. Some species may have been adapted to speed and swam in the tur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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