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Bifericeras
''Bifericeras'' is a Lower Jurassic ammonite belonging to the family Eoderoceratidae, and sometimes placed in the subfamily Xipherceratinae. Whorls are strongly depressed, but still evolute in coiling. The early growth state is prolonged, and smooth, followed by a late growth stage with rounded, straight, bituberculate ribs. ''Bifericeras'' was named by Buckman in 1913 and is found in Europe. Biostratigraphic significance The International Commission on Stratigraphy (ICS) has assigned the First Appearance Datum of ''Bifericeras donovani'' and of genus ''Apoderoceras'' the defining biological marker for the start of the Pliensbachian Stage of the Jurassic, 190.8 ± 1.0 million years ago. Distribution Only found at Dimmer Camp, Castle Cary, Somerset ( en, All The People of Somerset) , locator_map = , coordinates = , region = South West England , established_date = Ancient , established_by = , preceded_by = , origin = , lord_lieutenant_office =Lord Lieutenant of S ... [...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 genera ''Apoderocer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apoderoceras
''Apoderoceras'' is an extinct genus of cephalopod belonging to the ammonite subclass. Biostratigraphic significance The International Commission on Stratigraphy (ICS) has assigned the First Appearance Datum of genus ''Apoderoceras'' and of '' Bifericeras donovani'' the defining biological marker for the start of the Pliensbachian Stage of the 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 J ..., 190.8 ± 1.0 million years ago. Distribution Jurassic of Argentina, Hungary, Italy, Portugal, the United Kingdom References Eoderoceratoidea Ammonitida genera Jurassic ammonites of Europe Pliensbachian life {{Ammonitina-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jurassic Ammonites
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] |
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] |
List Of Global Boundary Stratotype Sections And Points
This is a list of Global Boundary Stratotype Sections and Points. Since 1977, Global Boundary Stratotype Sections and Points (abbreviated GSSPs) are internationally agreed upon reference points on stratigraphic sections of rock which define the lower boundaries of stages on the geologic time scale. They are selected by the International Commission on Stratigraphy based on multiple factors, but their accessibility and the degree to which they are representative of the same boundary on sections worldwide are among the most important. Since GSSPs require well-preserved sections of rock without interruptions in sedimentation, and since most are defined by different stages of animal life, defining them becomes progressively more difficult as one goes further back in time. Organization of this list This list is divided first into the geologic eras of the Phanerozoic (the Cenozoic, the Mesozoic, and the Paleozoic) and then into the geologic periods of each era. Each period is marked ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ammonoidea
Ammonoids are a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs, commonly referred to as ammonites, are more closely related to living coleoids (i.e., octopuses, squid and cuttlefish) than they are to shelled nautiloids such as the living ''Nautilus'' species. The earliest ammonites appeared during the Devonian, with the last species vanishing during the Cretaceous–Paleogene extinction event. Ammonites are excellent index fossils, and linking the rock layer in which a particular species or genus is found to specific geologic time periods is often possible. Their fossil shells usually take the form of planispirals, although some helically spiraled and nonspiraled forms (known as heteromorphs) have been found. The name "ammonite", from which the scientific term is derived, was inspired by the spiral shape of their fossilized shells, which somewhat resemble tightly coiled rams' horns. Pliny the Elder ( 79 AD nea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eoderoceratidae
Eoderoceratidae is the ancestral and most primitive family of the Eoderoceratoidea; lower Jurassic ammonite cephalopods, characterized by evolute, commonly serpenticonic, shells that had long body chambers and would have had no stable floating position; and thus resemble contemporary Psiloceratoidea. Spines, or tubercles, are typically found in two rows on the inner and outer parts of the whorl sides, joined by radial ribs. These are often more developed on the inner and middle whorls, becoming less so or absent on the outer. Sutures are highly complex. The Eoderoceratidae can be divided into two subfamilies, the Xiphoceratinae which is the earliest and in which there is an early maximum development of spines of the inner whorls, and the Eoderoceratinae. Two other subfamilies were included in the Treatise 1957 but are now regarded as families in their own right, These are the Phricodoceratidae and Coeloceratidae Genera that have been attributed to the Xiphoceratinae are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Animalia
Animals are multicellular, eukaryotic organisms in the biological kingdom Animalia. With few exceptions, animals consume organic material, breathe oxygen, are able to move, can reproduce sexually, and go through an ontogenetic stage in which their body consists of a hollow sphere of cells, the blastula, during embryonic development. Over 1.5 million living animal species have been described—of which around 1 million are insects—but it has been estimated there are over 7 million animal species in total. Animals range in length from to . They have complex interactions with each other and their environments, forming intricate food webs. The scientific study of animals is known as zoology. Most living animal species are in Bilateria, a clade whose members have a bilaterally symmetric body plan. The Bilateria include the protostomes, containing animals such as nematodes, arthropods, flatworms, annelids and molluscs, and the deuterostomes, containing the echinode ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Somerset
( en, All The People of Somerset) , locator_map = , coordinates = , region = South West England , established_date = Ancient , established_by = , preceded_by = , origin = , lord_lieutenant_office =Lord Lieutenant of Somerset , lord_lieutenant_name = Mohammed Saddiq , high_sheriff_office =High Sheriff of Somerset , high_sheriff_name = Mrs Mary-Clare Rodwell (2020–21) , area_total_km2 = 4171 , area_total_rank = 7th , ethnicity = 98.5% White , county_council = , unitary_council = , government = , joint_committees = , admin_hq = Taunton , area_council_km2 = 3451 , area_council_rank = 10th , iso_code = GB-SOM , ons_code = 40 , gss_code = , nuts_code = UKK23 , districts_map = , districts_list = County council area: , MPs = * Rebecca Pow (C) * Wera Hobhouse ( LD) * Liam Fox (C) * David Warburton (C) * Marcus Fysh (C) * Ian Liddell-Grainger (C) * James Heappey (C) * Jacob Rees-Mogg (C) * John Penrose (C) , police = Avon and Somerset Police ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Castle Cary
Castle Cary () is a market town and civil parish in south Somerset, England, north west of Wincanton and south of Shepton Mallet, at the foot of Lodge Hill and on the River Cary, a tributary of the Parrett. History The word Cary derives from the Celtic ''caer'' meaning rock, crag or castle, making the term Castle Cary a double-play. Castle Cary is said to take half its name from River Cary, itself an aporia. The first Cary Castle was besieged in 1138 and again in 1152. It was originally made of timber frame, as it would have been built by the Normans and inherited their building traditions in wood. Cary first appears in recorded history after the Norman invasion in the 11th century though according to Castle Cary history 'there is evidence the site was occupied and fortified before this. The second castle was abandoned by the mid-15th century in favour of a manor house and the stones pillaged for other buildings in the town. It would seem that the second castle was begun i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Commission On Stratigraphy
The International Commission on Stratigraphy (ICS), sometimes referred to unofficially as the "International Stratigraphic Commission", is a daughter or major subcommittee grade scientific daughter organization that concerns itself with stratigraphy, stratigraphical, geology, geological, and chronology, geochronological matters on a global scale. It is the largest subordinate body of the International Union of Geological Sciences (IUGS). The ICS is essentially a permanent working committee, working subcommittee, which meets far more regularly than the quadrennial meetings scheduled by the IUGS, when it meets as a congress or committee, membership of the whole. Aims One of its main aims, a project begun in 1974, is to establish a multidisciplinary standard and global geologic time scale that will ease paleontology, paleontological and geobiology, geobiological comparisons region to region by benchmarks with stringent and rigorous strata criteria called Global Boundary Stratotype ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
First Appearance Datum
First appearance datum (FAD) is a term used by geologists and paleontologists to designate the first appearance of a species in the geologic record. FADs are determined by identifying the geologically oldest fossil discovered, to date, of a particular species. A related term is last appearance datum (LAD), the last appearance of a species in the geologic record. FADs are frequently used to designate segments in the geologic time scale. A given FAD can be used to define a Global Boundary Stratotype Section and Point (GSSP). For example, the beginning of the Tremadocian Stage of the Ordovician Period is marked by the first appearance of the conodont ''Iapetognathus fluctivagus'' in the geologic record. This occurs in bed 23 of the rock formation known as the Green Point section, located in western Newfoundland, as well as in geologically correlated strata in many parts of the world. However, diachronous FADs can be problematic for correlating chronostratigraphic units, particularly o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
