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Passaloteuthis Apicicurvata
''Passaloteuthis'' is a genus of belemnite, an extinct group of cephalopods. Belemnites are typically known for having about 40 micro-hooks on each one of its appendage. However, ''Passaloteuthis'' is notable for being associated with a pair of mega-hooks known as onychites. These hooks are tentatively interpreted as male-specific features, though their exact function is still unknown. See also * Belemnite * List of belemnites References Belemnites {{paleo-cephalopod-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pliensbachian
The Pliensbachian is an age of the geologic timescale and stage in the stratigraphic column. It is part of the Early or Lower Jurassic Epoch or Series and spans the time between 190.8 ± 1.5 Ma and 182.7 ± 1.5 Ma (million years ago). The Pliensbachian is preceded by the Sinemurian and followed by the Toarcian. The Pliensbachian ended with the extinction event called the Toarcian turnover. During the Pliensbachian, the middle part of the Lias was deposited in Europe. The Pliensbachian is roughly coeval with the Charmouthian regional stage of North America. Stratigraphic definitions The Pliensbachian takes its name from the hamlet of Pliensbach in the community of Zell unter Aichelberg in the Swabian Alb, some 30 km east of Stuttgart in Germany. The name was introduced into scientific literature by German palaeontologist Albert Oppel in 1858. The base of the Pliensbachian is at the first appearances of the ammonite species '' Bifericeras donovani'' and gene ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toarcian
The Toarcian is, in the ICS' geologic timescale, an age and stage in the Early or Lower Jurassic. It spans the time between 182.7 Ma (million years ago) and 174.1 Ma. It follows the Pliensbachian and is followed by the Aalenian. The Toarcian Age began with the Toarcian turnover, the extinction event that sets its fossil faunas apart from the previous Pliensbachian age. It is believed to have ended with a global cooling event known as the Comptum Cooling Event, although whether it represented a worldwide event is controversial. Stratigraphic definitions The Toarcian takes its name from the city of Thouars, just south of Saumur in the Loire Valley of France. The stage was introduced by French palaeontologist Alcide d'Orbigny in 1842, after examining rock strata of this age in a quarry near Thouars. In Europe this period is represented by the upper part of the Lias. The base of the Toarcian is defined as the place in the stratigraphic record where the ammonite genu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lower Lias
The Lias Group or Lias is a lithostratigraphic unit (a sequence of rock strata) found in a large area of western Europe, including the British Isles, the North Sea, the Low Countries and the north of Germany. It consists of marine limestones, shales, marls and clays. ''Lias'' is a Middle English term for hard limestone, used in this specific sense by geologists since 1833. In the past, geologists used ''Lias'' not only for the sequence of rock layers, but also for the timespan during which they were formed. It was thus an alternative name for the Early Jurassic epoch of the geologic timescale. It is now more specifically known that the Lias is Rhaetian to Toarcian in age (over a period of 20 million years between ) and thus also includes a part of the Triassic. The use of the name "Lias" for a unit of time is therefore slowly disappearing. Subdivisions In southern England, the Lias Group is often divided into Lower, Middle and Upper subgroups. In Southern England the Lias is d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gloucestershire
Gloucestershire ( abbreviated Glos) is a county in South West England. The county comprises part of the Cotswold Hills, part of the flat fertile valley of the River Severn and the entire Forest of Dean. The county town is the city of Gloucester and other principal towns and villages include Cheltenham, Cirencester, Kingswood, Bradley Stoke, Stroud, Thornbury, Yate, Tewkesbury, Bishop's Cleeve, Churchdown, Brockworth, Winchcombe, Dursley, Cam, Berkeley, Wotton-under-Edge, Tetbury, Moreton-in-Marsh, Fairford, Lechlade, Northleach, Stow-on-the-Wold, Chipping Campden, Bourton-on-the-Water, Stonehouse, Nailsworth, Minchinhampton, Painswick, Winterbourne, Frampton Cotterell, Coleford, Cinderford, Lydney and Rodborough and Cainscross that are within Stroud's urban area. Gloucestershire borders Herefordshire to the north-west, Worcestershire to the north, Warwickshire to the north-east, Oxfordshire to the east, Wiltshire to the south, Bristol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus. :E.g. '' Panthera leo'' (lion) and '' Panthera onca'' (jaguar) are two species within the genus ''Panthera''. ''Panthera'' is a genus within the family Felidae. The composition of a genus is determined by taxonomists. The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including the idea that a newly defined genus should fulfill these three criteria to be descriptively useful: # monophyly – all descendants of an ancestral taxon are grouped together (i.e. phylogenetic analysis should c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Belemnite
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 tu ... [...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 i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Passaloteuthis
''Passaloteuthis'' is a genus of belemnite, an extinct group of cephalopods. Belemnites are typically known for having about 40 micro-hooks on each one of its appendage. However, ''Passaloteuthis'' is notable for being associated with a pair of mega-hooks known as onychites. These hooks are tentatively interpreted as male-specific features, though their exact function is still unknown. See also * Belemnite 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 ... * List of belemnites References Belemnites {{paleo-cephalopod-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Belemnite
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 tu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Belemnites
This list of belemnite genera is an attempt to create a comprehensive listing of all genera that have ever been included in the extinct subclass Belemnoidea, excluding purely vernacular terms. The list includes all commonly accepted genera, as well as 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 belemites. Naming conventions and terminology follow the International Code of Zoological Nomenclature as indicated. The list currently contains 100 generic names. List of belemnites See also * Belemnoidea * List of ammonites * 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 :''Unc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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