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Clevosaurus Brasiliensis
''Clevosaurus'' (meaning "Gloucester lizard") is an extinct genus of rhynchocephalian reptile from the Late Triassic and the Early Jurassic periods. Species of ''Clevosaurus'' were widespread across Pangaea, and have been found on all continents except Australia and Antarctica. Five species of ''Clevosaurus'' have been found in ancient fissure fill deposits in south-west England and Wales, alongside other sphenodontians, early mammals and dinosaurs. In regards to its Pangaean distribution, ''C. hadroprodon'' is the oldest record of a sphenodontian from Gondwana, though its affinity to ''Clevosaurus'' has been questioned. History of discovery The first species of ''Clevosaurus'' to be described was ''C. hudsoni'', which was described by William Elgin Swinton in 1939 from a fissure fill deposit in Cromhall Quarry ( Magnesian Conglomerate Formation) in the county of Gloucestershire, England, with the name of the county lending its name to the genus. Description ''Clevosaurus'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Triassic
The Late Triassic is the third and final epoch (geology), epoch of the Triassic geologic time scale, Period in the geologic time scale, spanning the time between annum, Ma and Ma (million years ago). It is preceded by the Middle Triassic Epoch and followed by the Early Jurassic Epoch. The corresponding series (stratigraphy), series of rock beds is known as the Upper Triassic. The Late Triassic is divided into the Carnian, Norian and Rhaetian Geologic time scale, Ages. Many of the first dinosaurs evolved during the Late Triassic, including ''Plateosaurus'', ''Coelophysis'', and ''Eoraptor''. The Triassic–Jurassic extinction event began during this epoch and is one of the five major mass extinction events of the Earth. Etymology The Triassic was named in 1834 by Friedrich August von Namoh, Friedrich von Alberti, after a succession of three distinct rock layers (Greek meaning 'triad') that are widespread in southern Germany: the lower Buntsandstein (colourful sandstone'')'', t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hettangian
The Hettangian is the earliest age and lowest 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 ... Geological time scale, Period of the geologic timescale. It spans the time between 201.3 ± 0.2 annum, Ma and 199.3 ± 0.3 Ma (million years ago). The Hettangian follows the Rhaetian (part of the Triassic Period) and is followed by the Sinemurian. In European stratigraphy the Hettangian is a part of the time span in which the Lias Group, Lias was deposited. An example is the British Blue Lias, which has an upper Rhaetian to Sinemurian age. Another example is the lower Lias from the Northern Limestone Alps where well-preserved but very rare ammonites, including Alsatites, have been found. Stratigraphic definitions The Hettangian was introduced in the literature by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phylogenetic Analysis
In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups of organisms. These relationships are determined by Computational phylogenetics, phylogenetic inference methods that focus on observed heritable traits, such as DNA sequences, protein amino acid sequences, or morphology. The result of such an analysis is a phylogenetic tree—a diagram containing a hypothesis of relationships that reflects the evolutionary history of a group of organisms. The tips of a phylogenetic tree can be living taxa or fossils, and represent the "end" or the present time in an evolutionary lineage. A phylogenetic diagram can be rooted or unrooted. A rooted tree diagram indicates the hypothetical common ancestor of the tree. An unrooted tree diagram (a network) makes no assumption about the ancestral line, and does n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cladogram
A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to descendants, nor does it show how much they have changed, so many differing evolutionary trees can be consistent with the same cladogram. A cladogram uses lines that branch off in different directions ending at a clade, a group of organisms with a last common ancestor. There are many shapes of cladograms but they all have lines that branch off from other lines. The lines can be traced back to where they branch off. These branching off points represent a hypothetical ancestor (not an actual entity) which can be inferred to exhibit the traits shared among the terminal taxa above it. This hypothetical ancestor might then provide clues about the order of evolution of various features, adaptation, and other evolutionary narratives about ance ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clarens Formation
The Clarens Formation is a geological formation found in several localities in Lesotho and in the Free State, KwaZulu-Natal, and Eastern Cape provinces in South Africa. It is the uppermost of the three formations found in the Stormberg Group of the greater Karoo Supergroup rocks and represents the final phase of preserved sedimentation of the Karoo Basin. Geology The Clarens Formation is composed nearly entirely of fine to medium-grained, thickly-bedded sandstones that range from pale orange or pinkish to cream in color. It is characterized by its remarkable gross lithological uniformity and that its deposits mainly outcrop as high cliffs. These Clarens Formation cliffs frequently contain shallow caves and overhangs at the contact of the underlying Upper Elliot Formation (UEF) due to processes of erosion. This particular feature of the Clarens Formation lead to the initial naming of these rocks the “Cave Sandstone” in older literature. It is thought that the geographical ra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elliot Formation
The Elliot Formation is a geological formation and forms part of the Stormberg Group, the uppermost geological Stratigraphic unit, group that comprises the greater Karoo Supergroup. Outcrops of the Elliot Formation have been found in the northern Eastern Cape, southern Free State (province), Free State, and in the eastern KwaZulu-Natal provinces of South Africa. Outcrops and exposures are also found in several localities in Lesotho such as Qacha's Nek, Qacha's Neck, Hill Top, Quthing, and near the capital, Maseru. The Elliot Formation is further divided into the lower (LEF) and upper (UEF) Elliot formations to differentiate significant Sedimentology, sedimentological differences between these layers. The LEF is dominantly Late Triassic (Norian-Hettangian) in age while the UEF is mainly Early Jurassic (Sinemurian-Pliensbachian) and is tentatively regarded to preserve a continental record of the Triassic–Jurassic extinction event, Triassic-Jurassic boundary in southern Africa. This ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stormberg Group
The Stormberg Group is one of the four geological groups that comprises the Karoo Supergroup in South Africa. It is the uppermost geological group representing the final phase of preserved sedimentation of the Karoo Basin. The Stormberg Group rocks are considered to range between Lower Triassic (Olenekian) to Lower Jurassic (Pliensbachian) in age. These estimates are based on means of geological dating including stratigraphic position, lithostratigraphic and biostratigraphic correlations, and palynological analyses. Background Sediment deposition of the Stormberg Group took place in a terrestrial environment that was seasonally arid. The depositional environment in the lower sections of the Stormberg was similar to that of the Katberg Formation. Both places feature coarser-grained sandstones that lack fining-upward sequences, thus pointing to an alluvial fan and braided river environment. The depositional environment changes towards the centre of the Stormberg as mudstones becom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lufeng Formation
The Lufeng Formation (formerly Lower Lufeng Series) is a Lower Jurassic sedimentary rock formation found in Yunnan, China. It has two units: the lower Dull Purplish Beds/Shawan Member are of Hettangian age, and Dark Red Beds/Zhangjia'ao Member are of Sinemurian age.Luo, Z., and X.-C. Wu. 1994. The small tetrapods of the Lower Lufeng Formation, Yunnan, China; pp. 251–270 in N. C. Fraser and H.-D.Sues (eds.), In the Shadow of the Dinosaurs. Cambridge University Press, New York It is known for its fossils of early dinosaurs. The Dull Purplish Beds have yielded the possible therizinosaur ''Eshanosaurus'', the possible theropod ''Lukousaurus'', and the "prosauropods" "Gyposaurus" ''sinensis'', ''Lufengosaurus'', ''Jingshanosaurus'', and ''Yunnanosaurus''. Dinosaurs discovered in the Dark Red Beds include the theropod ''Sinosaurus triassicus'', the "prosauropods" "Gyposaurus", ''Lufengosaurus'', and ''Yunnanosaurus'', indeterminate remains of sauropods, and the early armored dino ... [...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] |
Carnian
The Carnian (less commonly, Karnian) is the lowermost stage of the Upper Triassic Series (or earliest age of the Late Triassic Epoch). It lasted from 237 to 227 million years ago (Ma). The Carnian is preceded by the Ladinian and is followed by the Norian. Its boundaries are not characterized by major extinctions or biotic turnovers, but a climatic event (known as the Carnian pluvial episode characterized by substantial rainfall) occurred during the Carnian and seems to be associated with important extinctions or biotic radiations. Stratigraphic definitions The Carnian was named in 1869 by Mojsisovics. It is unclear if it was named after the Carnic Alps or after the Austrian region of Carinthia (''Kärnten'' in German) or after the Carnia historical region in northwestern Italy. The name, however, was first used referring to a part of the Hallstatt Limestone cropping out in Austria. The base of the Carnian Stage is defined as the place in the stratigraphic record where t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Santa Maria Formation
The Santa Maria Formation is a sedimentary rock formation found in Rio Grande do Sul, Brazil. It is primarily Carnian in age (Late Triassic), and is notable for its fossils of cynodonts, "rauisuchian" pseudosuchians, and early dinosaurs and other dinosauromorphs, including the herrerasaurid '' Staurikosaurus'', the basal sauropodomorphs ''Buriolestes'' and '' Saturnalia,'' and the lagerpetid ''Ixalerpeton''. The formation is named after the city of Santa Maria in the central region of Rio Grande do Sul, where outcrops were first studied. The Santa Maria Formation makes up the majority of the Santa Maria Supersequence, which extends through the entire Late Triassic. The Santa Maria Supersequence is divided into four geological sequences, separated from each other by short unconformities. The first two of these sequences (Pinheiros-Chiniquá and Santa Cruz sequences) lie entirely within the Santa Maria Formation, while the third (the Candelária sequence) is shared with the ov ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhaetian
The Rhaetian is the latest age of the Triassic Period (in geochronology) or the uppermost stage of the Triassic System (in chronostratigraphy). It was preceded by the Norian and succeeded by the Hettangian (the lowermost stage or earliest age of the Jurassic). The base of the Rhaetian lacks a formal GSSP, though candidate sections include Steinbergkogel in Austria (since 2007) and Pignola-Abriola in Italy (since 2016). The end of the Rhaetian (and the base of the overlying Hettangian Stage) is more well-defined. According to the current ICS (International Commission on Stratigraphy) system, the Rhaetian ended ± 0.2 Ma (million years ago). In 2010, the base of the Rhaetian (i.e. the Norian-Rhaetian boundary) was voted to be defined based on the first appearance of '' Misikella posthernsteini'', a marine conodont. However, there is still much debate over the age of this boundary, as well as the evolution of ''M. posthernsteini''. The most comprehensive source of precise age ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
