Azhdarcho
Azhdarcho is a genus of pterodactyloid pterosaur from the late Cretaceous Period of the Bissekty Formation of Uzbekistan. It is known from fragmentary remains including the distinctive, elongated neck vertebrae that characterizes members of the family Azhdarchidae, which includes such giant pterosaurs as Quetzalcoatlus; the name Azhdarcho comes from a dragon-like creature in Persian mythology. The type species is Azhdarcho lancicollis; the specific epithet lancicollis is derived from the Latin words collum. The fossil remains of Azhdarcho were recovered in the Kyzyl Kum desert by Lev A. Nesov during expeditions to Central Asia in 1974-1981; the type specimen, given the catalog number ЦНИГРмузей 1/11915, consists of an anterior neck vertebra. Twelve paratypes were referred, including several other neck vertebrae, elements from the wing and leg, pieces of the jaw; these specimens, along with other vertebrate fossils collected during the expeditions, were deposited at the F. N. Chernyshev Central Geologic Exploration Museum in St. Petersberg.
In his description of the type specimen of Azhdarcho lancicollis, Nesov noted its distinctive neck vertebrae, which are elongated and round in cross section at mid-length. He pointed out similar characteristics in several other pterosaurs, used them to erect the new subfamily Azhdarchinae, within the Pteranodontidae. Nesov referred Quetzalcoatlus and Arambourgiania to this subfamily, subsequently re-classified as the family Azhdarchidae, he suggested that similar, thin-walled pterosaur bones from the Lance Formation of Wyoming could be assigned to a species of Azhdarcho, using this as evidence of commonalities between the fauna of Late Cretaceous central Asia and western North America. However, subsequent research has not followed this suggestion, A. lancicollis is the only recognized species of Azhdarcho. In the original description of Azhdarcho, Nesov noted that because of the way the vertebrae articulated, the pterosaur would have had limited flexibility in the neck. Azhdarcho could not rotate its neck at all, though it could flex the neck vertically to a certain degree.
Nesov suggested that pterosaurs like Azhdarcho may have fed in a manner similar to the modern Skimmer, with their long necks allowing them to scoop prey from the water's surface and small depths without needing to dive. However, recent research has shown that skimming requires more energy and anatomical specializations than thought, that large pterosaurs like Azhdarcho were not capable of skimming; the long neck would have allowed azhdarchids to hunt for food in the water or on the bottom while swimming, or to hunt poorly flying vertebrates in the air, though Nesov suggested that the animal would have needed stable weather conditions to fly well, suggested azhdarchid habitats needed to be dominated by mild winds. However studies by Mark Witton points to a different direction suggesting that Azhdarchids in general were terrestrial stalkers. Timeline of pterosaur research
Type species
In zoological nomenclature, a type species is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e. the species that contains the biological type specimen. A similar concept is used for suprageneric groups called a type genus. In botanical nomenclature, these terms have no formal standing under the code of nomenclature, but are sometimes borrowed from zoological nomenclature. In botany, the type of a genus name is a specimen, the type of a species name; the species name that has that type can be referred to as the type of the genus name. Names of genus and family ranks, the various subdivisions of those ranks, some higher-rank names based on genus names, have such types. In bacteriology, a type species is assigned for each genus; every named genus or subgenus in zoology, whether or not recognized as valid, is theoretically associated with a type species. In practice, there is a backlog of untypified names defined in older publications when it was not required to specify a type.
A type species is both a concept and a practical system, used in the classification and nomenclature of animals. The "type species" represents the reference species and thus "definition" for a particular genus name. Whenever a taxon containing multiple species must be divided into more than one genus, the type species automatically assigns the name of the original taxon to one of the resulting new taxa, the one that includes the type species; the term "type species" is regulated in zoological nomenclature by article 42.3 of the International Code of Zoological Nomenclature, which defines a type species as the name-bearing type of the name of a genus or subgenus. In the Glossary, type species is defined as The nominal species, the name-bearing type of a nominal genus or subgenus; the type species permanently attaches a formal name to a genus by providing just one species within that genus to which the genus name is permanently linked. The species name in turn is fixed, to a type specimen. For example, the type species for the land snail genus Monacha is Helix cartusiana, the name under which the species was first described, known as Monacha cartusiana when placed in the genus Monacha.
That genus is placed within the family Hygromiidae. The type genus for that family is the genus Hygromia; the concept of the type species in zoology was introduced by Pierre André Latreille. The International Code of Zoological Nomenclature states that the original name of the type species should always be cited, it gives an example in Article 67.1. Astacus marinus Fabricius, 1775 was designated as the type species of the genus Homarus, thus giving it the name Homarus marinus. However, the type species of Homarus should always be cited using its original name, i.e. Astacus marinus Fabricius, 1775. Although the International Code of Nomenclature for algae and plants does not contain the same explicit statement, examples make it clear that the original name is used, so that the "type species" of a genus name need not have a name within that genus, thus in Article 10, Ex. 3, the type of the genus name Elodes is quoted as the type of the species name Hypericum aegypticum, not as the type of the species name Elodes aegyptica.
Glossary of scientific naming Genetypes – genetic sequence data from type specimens. Holotype Paratype Principle of Typification Type Type genus
Pterosaur
Pterosaurs were flying reptiles of the extinct clade or order Pterosauria. They existed during most of the Mesozoic: from the late Triassic to the end of the Cretaceous. Pterosaurs are the earliest vertebrates known to have evolved powered flight, their wings were formed by a membrane of skin and other tissues stretching from the ankles to a lengthened fourth finger. Early species had long toothed jaws and long tails, while forms had a reduced tail, some lacked teeth. Many sported furry coats made up of hair-like filaments known as pycnofibers, which covered their bodies and parts of their wings. Pterosaurs spanned a wide range of adult sizes, from the small anurognathids to the largest known flying creatures of all time, including Quetzalcoatlus and Hatzegopteryx. Pterosaurs are referred to in the popular media and by the general public as "flying dinosaurs", but the term "dinosaur" is restricted to just those reptiles descended from the last common ancestor of the groups Saurischia and Ornithischia, current scientific consensus is that this group excludes the pterosaurs, as well as the various groups of extinct marine reptiles, such as ichthyosaurs and mosasaurs.
Unlike these other reptiles, pterosaurs are nonetheless more related to birds and dinosaurs than to crocodiles or any other living reptile. Pterosaurs are colloquially referred to as pterodactyls in fiction and by journalists. However, pterodactyl only refers to members of the genus Pterodactylus, more broadly to members of the suborder Pterodactyloidea of the pterosaurs; the anatomy of pterosaurs was modified from their reptilian ancestors by the adaption to flight. Pterosaur bones were air-filled, like the bones of birds, they had a keeled breastbone, developed for the attachment of flight muscles and an enlarged brain that shows specialised features associated with flight. In some pterosaurs, the backbone over the shoulders fused into a structure known as a notarium, which served to stiffen the torso during flight, provide a stable support for the shoulder blade. Pterosaur wings were formed by membranes of skin and other tissues; the primary membranes attached to the long fourth finger of each arm and extended along the sides of the body to the ankles.
While thought of as simple leathery structures composed of skin, research has since shown that the wing membranes of pterosaurs were complex dynamic structures suited to an active style of flight. The outer wings were strengthened by spaced fibers called actinofibrils; the actinofibrils themselves consisted of three distinct layers in the wing, forming a crisscross pattern when superimposed on one another. The function of the actinofibrils is unknown. Depending on their exact composition, they may have been stiffening or strengthening agents in the outer part of the wing; the wing membranes contained a thin layer of muscle, fibrous tissue, a unique, complex circulatory system of looping blood vessels. As shown by cavities in the wing bones of larger species and soft tissue preserved in at least one specimen, some pterosaurs extended their system of respiratory air sacs into the wing membrane; the pterosaur wing membrane is divided into three basic units. The first, called the propatagium, was the forward-most part of the wing and attached between the wrist and shoulder, creating the "leading edge" during flight.
This membrane may have incorporated the first three fingers of the hand, as evidenced in some specimens. The brachiopatagium was the primary component of the wing, stretching from the elongated fourth finger of the hand to the hind limbs. At least some pterosaur groups had a membrane that stretched between the legs connecting to or incorporating the tail, called the uropatagium, it is agreed though that non-pterodactyloid pterosaurs had a broader uro/cruropatagium, with pterodactyloids only having membranes running along the legs. A bone unique to pterosaurs, known as the pteroid, connected to the wrist and helped to support a forward membrane between the wrist and shoulder. Evidence of webbing between the three free fingers of the pterosaur forelimb suggests that this forward membrane may have been more extensive than the simple pteroid-to-shoulder connection traditionally depicted in life restorations; the position of the pteroid bone itself has been controversial. Some scientists, notably Matthew Wilkinson, have argued that the pteroid pointed forward, extending the forward membrane.
This view was contradicted in a 2007 paper by Chris Bennett, who showed that the pteroid did not articulate as thought and could not have pointed forward, but rather inward toward the body as traditionally thought. Peters proposed that the pteroid articulated with the ‘saddle' of the radiale and both the pteroid and preaxial carpal were migrated centralia; this view of the articulation of the pteroid has since been supported by specimens of Changchengopterus pani and Darwinopterus linglongtaensis, both of which show the pteroid in articulation with the proximal syncarpal. The pterosaur
Mongolia
Mongolia is a landlocked country in East Asia. Its area is equivalent with the historical territory of Outer Mongolia, that term is sometimes used to refer to the current state, it is sandwiched between China to Russia to the north. Mongolia does not share a border with Kazakhstan. At 1,564,116 square kilometres, Mongolia is the 18th-largest and the most sparsely populated sovereign state in the world, with a population of around three million people, it is the world's second-largest landlocked country behind Kazakhstan and the largest landlocked country that does not border a closed sea. The country contains little arable land, as much of its area is covered by grassy steppe, with mountains to the north and west and the Gobi Desert to the south. Ulaanbaatar, the capital and largest city, is home to about 45% of the country's population. Ulaanbaatar shares the rank of the world's coldest capital city with Moscow and Nur-Sultan. 30% of the population is nomadic or semi-nomadic. The majority of its population are Buddhists.
The non-religious population is the second largest group. Islam is the dominant religion among ethnic Kazakhs; the majority of the state's citizens are of Mongol ethnicity, although Kazakhs and other minorities live in the country in the west. Mongolia joined the World Trade Organization in 1997 and seeks to expand its participation in regional economic and trade groups; the area of what is now Mongolia has been ruled by various nomadic empires, including the Xiongnu, the Xianbei, the Rouran, the Turkic Khaganate, others. In 1206, Genghis Khan founded the Mongol Empire, which became the largest contiguous land empire in history, his grandson Kublai Khan conquered China to establish the Yuan dynasty. After the collapse of the Yuan, the Mongols retreated to Mongolia and resumed their earlier pattern of factional conflict, except during the era of Dayan Khan and Tumen Zasagt Khan. In the 16th century, Tibetan Buddhism began to spread in Mongolia, being further led by the Manchu-founded Qing dynasty, which absorbed the country in the 17th century.
By the early 1900s one-third of the adult male population were Buddhist monks. After the collapse of the Qing dynasty in 1911, Mongolia declared independence, achieved actual independence from the Republic of China in 1921. Shortly thereafter, the country came under the control of the Soviet Union, which had aided its independence from China. In 1924, the Mongolian People's Republic was founded as a socialist state. After the anti-Communist revolutions of 1989, Mongolia conducted its own peaceful democratic revolution in early 1990; this led to a multi-party system, a new constitution of 1992, transition to a market economy. Homo erectus inhabited Mongolia from 850,000 years ago. Modern humans reached Mongolia 40,000 years ago during the Upper Paleolithic; the Khoit Tsenkher Cave in Khovd Province shows lively pink and red ochre paintings of mammoths, bactrian camels, ostriches, earning it the nickname "the Lascaux of Mongolia". The venus figurines of Mal'ta testify to the level of Upper Paleolithic art in northern Mongolia.
Neolithic agricultural settlements, such as those at Norovlin, Tamsagbulag and Rashaan Khad, predated the introduction of horse-riding nomadism, a pivotal event in the history of Mongolia which became the dominant culture. Horse-riding nomadism has been documented by archeological evidence in Mongolia during the Copper and Bronze Age Afanasevo culture; the wheeled vehicles found in the burials of the Afanasevans have been dated to before 2200 BC. Pastoral nomadism and metalworking became more developed with the Okunev culture, Andronovo culture and Karasuk culture, culminating with the Iron Age Xiongnu Empire in 209 BC. Monuments of the pre-Xiongnu Bronze Age include deer stones, keregsur kurgans, square slab tombs, rock paintings. Although cultivation of crops has continued since the Neolithic, agriculture has always remained small in scale compared to pastoral nomadism. Agriculture arose independently in the region; the population during the Copper Age has been described as mongoloid in the east of what is now Mongolia, as europoid in the west.
Tocharians and Scythians inhabited western Mongolia during the Bronze Age. The mummy of a Scythian warrior, believed to be about 2,500 years old, was a 30- to 40-year-old man with blond hair; as equine nomadism was introduced into Mongolia, the political center of the Eurasian Steppe shifted to Mongolia, where it remained until the 18th century CE. The intrusions of northern pastoralists into China during the Shang dynasty and Zhou dynasty presaged the age of nomadic empires; the concept of Mongolia as an independent power north of China is expressed in a letter sent by Emperor Wen of Han to Laoshang Chanyu in 162 BC: Since prehistoric times, Mongolia has been inhabited by nomads who, from time to time, formed great confederations that rose to power and prominence. Common institutions were the office of the Khan, the Kurultai and right wings, imperial army and the decimal military system; the first of these empires, the Xiongnu of undetermined
Noripterus
Noripterus is a genus of dsungaripterid pterodactyloid pterosaur from Lower Cretaceous-age Lianmuqin Formation in the Junggar Basin of Xinjiang, China. It was first named by Yang Zhongjian in 1973. Additional fossil remains have been recovered from Mongolia; the first, holotype specimen of Noripterus preserved the front part of the skull and lower jaws and partial limbs and pelvis. Noripterus was quite similar to the contemporaneous Dsungaripterus, though it was estimated to be a third shorter, it has long narrow neck vertebrae and, like Dsungaripterus, a crest and no teeth in the front of the lower jaw. The teeth that are present are well-developed and spaced far apart; the sharp snout is straight and not pointed upwards as with Dsungaripterus. Because of its similarity to Dsungaripterus, Noripterus has been assigned to the family Dsungaripteridae; the genus Phobetor, was in 1982 described by Natasha Bakhurina as a species of Dsungaripterus, based on a single lower leg bone, PIN 3953. The discovery of more remains among which an complete skull, GIN 100/31, was reason for Bakhurina to name D. parvus in 1986 as a separate genus, the species name became Phobetor parvus.
However, the genus name Phobetor was being used as a junior synonym of a species of sculpin, the arctic staghorn sculpin, Gymnocanthus tricuspis and thus unavailable. In 2009, Lü and colleagues re-examined much of the known dsungaripterid fossil material, found that "Phobetor" was indistinguishable from Noripterus, causing them to refer to it as a junior synonym. Assigning the "Phobetor" material to Noripterus increases the known size of the latter as it indicates a maximum wingspan of 4 metres. Dsungaripterids like Noripterus are interpreted as adapted for feeding on shellfish or other hard foodstuffs, with long narrow toothless beak tips for probing and picking up suitable prey, robust teeth farther back for cracking shells; the skulls of these animals are more robust than those of other pterosaurs, as well as their limbs and vertebrae. Noripterus lived in the same time and place as the larger Dsungaripterus, in formations that indicate the presence of extensive inland lake systems; because Noripterus had a more built skull with weaker, more slender teeth than its larger contemporary, it is that the two pterosaurs occupied separate ecological niches.
Like most dsungaripteroids, Noripterus was well adapted to a terrestrial lifestyle, bearing thick bone walls and stouty bodily proportions. List of pterosaur genera Timeline of pterosaur research
Holotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype. Under the International Code of Zoological Nomenclature, a holotype is one of several kinds of name-bearing types. In the International Code of Nomenclature for algae and plants and ICZN the definitions of types are similar in intent but not identical in terminology or underlying concept. For example, the holotype for the butterfly Lycaeides idas longinus is a preserved specimen of that species, held by the Museum of Comparative Zoology at Harvard University. An isotype is a duplicate of the holotype and is made for plants, where holotype and isotypes are pieces from the same individual plant or samples from the same gathering. A holotype is not "typical" of that taxon, although ideally it should be. Sometimes just a fragment of an organism is the holotype in the case of a fossil.
For example, the holotype of Pelorosaurus humerocristatus, a large herbivorous dinosaur from the early Jurassic period, is a fossil leg bone stored at the Natural History Museum in London. If a better specimen is subsequently found, the holotype is not superseded. Under the ICN, an additional and clarifying type could be designated an epitype under Article 9.8, where the original material is demonstrably ambiguous or insufficient. A conserved type is sometimes used to correct a problem with a name, misapplied. In the absence of a holotype, another type may be selected, out of a range of different kinds of type, depending on the case, a lectotype or a neotype. For example, in both the ICN and the ICZN a neotype is a type, appointed in the absence of the original holotype. Additionally, under the ICZN the Commission is empowered to replace a holotype with a neotype, when the holotype turns out to lack important diagnostic features needed to distinguish the species from its close relatives. For example, the crocodile-like archosaurian reptile Parasuchus hislopi Lydekker, 1885 was described based on a premaxillary rostrum, but this is no longer sufficient to distinguish Parasuchus from its close relatives.
This made. Texan paleontologist Sankar Chatterjee proposed that a new type specimen, a complete skeleton, be designated; the International Commission on Zoological Nomenclature considered the case and agreed to replace the original type specimen with the proposed neotype. The procedures for the designation of a new type specimen when the original is lost come into play for some recent, high-profile species descriptions in which the specimen designated as the holotype was a living individual, allowed to remain in the wild. In such a case, there is no actual type specimen available for study, the possibility exists that—should there be any perceived ambiguity in the identity of the species—subsequent authors can invoke various clauses in the ICZN Code that allow for the designation of a neotype. Article 75.3.7 of the ICZN requires that the designation of a neotype must be accompanied by "a statement that the neotype is, or upon publication has become, the property of a recognized scientific or educational institution, cited by name, that maintains a research collection, with proper facilities for preserving name-bearing types, that makes them accessible for study", but there is no such requirement for a holotype.
Type Allotype Paratype Type species Genetypes- genetic sequence data from type specimens. BOA Photographs of type specimens of Neotropical Rhopalocera
Thalassodromidae
Thalassodromidae or Thalassodrominae is a group of azhdarchoid pterosaurs from the early Cretaceous period of Brazil. They are considered either to be a distinct family within the clade Neoazdarchia related to dsungaripterids or azhdarchids, or alternatively a subfamily of the family Tapejaridae. Thalassodromidae traditionally includes only two genera and Tupuxuara, was defined to include them and any other descendants of their most recent common ancestor; the classification of thalassodromids is controversial. Some studies, including one by Lü and colleagues in 2008, have found that the thalassodromids are more related to the azhdarchids than to the tapejarids, have placed them in their own family. Alternately, they have been considered a subfamily within the Tapejaridae. Below are three alternate cladograms resulting from studies of azhdarchoid relationships; the first, presented by Felipe Pinheiro and colleagues in 2011, found the thalassodromids as subgroup within the Tapejaridae. The second, presented by Lu and colleagues in 2008, found them to be closer to the Azhdarchidae.
The third, presented by Andres, Clark & Xu, 2014 found thalassodromids closer to azhdarchids and as the sister group of the dsungaripterids. More the Late Cretaceous Alanqa and Aerotitan considered azhdarchids, have been recovered as thalassodromids, though their remains are fragmentary enough that this judgement is only tentative
