parent_taxon sarmatosuchus
Moscow ( or ) is the capital and most populous city of Russia , with 12 . 2 million residents within the city limits and 16 . 8 million within the urban ___MASK42___ . Moscow has the status of a Russian federal city . Crocodiles ( subfamily Crocodylinae ) or true crocodiles are large aquatic reptiles that live throughout the tropics in Africa , Asia , the Americas and Australia . Crocodylinae , all of whose members are considered true crocodiles , is classified as a biological subfamily . A broader sense of the term ___MASK70___ , Crocodylidae that includes " Tomistoma ", is not used in this article . The term ___MASK70___ here applies only to the species within the subfamily of Crocodylinae . The term is sometimes used even more loosely to include all extant members of the order Crocodilia , which includes " Tomistoma ", the alligators and caimans ( family Alligatoridae ), the gharials ( family Gavialidae ), and all other living and fossil ___MASK15___ . The Permian is a geologic period and system which spans 46 . 7 million years from the end of the Carboniferous Period million years ago ( ___MASK77___ ), to the beginning of the Triassic Period 252 . 2 ___MASK77___ . It is the last period of the Paleozoic Era ; the following Triassic Period belongs to the Mesozoic Era . The concept of the Permian was introduced in 1841 by geologist Sir Roderick Murchison , who named it after the city of Perm . A genus ( genera ) is a taxonomic rank used in the biological classification of living and fossil organisms in biology . 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 . Snakes are elongated , legless , carnivorous reptiles of the suborder Serpentes that can be distinguished from legless lizards by their lack of eyelids and external ears . Like all squamates , snakes are ectothermic , amniote vertebrates covered in overlapping scales . Many species of snakes have skulls with several more joints than their ___MASK5___ ancestors , enabling them to swallow prey much larger than their heads with their highly mobile jaws . To accommodate their narrow bodies , snakes ' paired organs ( such as kidneys ) appear one in front of the other instead of side by side , and most have only one functional lung . Some species retain a pelvic girdle with a pair of vestigial claws on either side of the cloaca . The Triassic is a geologic period and system which spans 50 . 9 million years from the end of the Permian Period million years ago ( ___MASK77___ ), to the beginning of the Jurassic Period ___MASK77___ . The Triassic is the first period of the Mesozoic Era . Both the start and end of the period are marked by major extinction events . The Triassic was named in 1834 by Friedrich von Alberti , after the three distinct rock layers (" tri " meaning " three ") that are found throughout Germany and northwestern Europe  red beds , capped by marine limestone , followed by a series of terrestrial mud - and sandstones  called the " Trias ". ___MASK58___ ( called amphisbaenians or worm lizards ) is a group of usually legless squamates , comprising over 180 extant species . Amphisbaenians are characterized by their long bodies , the reduction or loss of the limbs , and rudimentary eyes . As many species have a pink body and scales arranged in rings , they have a superficial resemblance to earthworms . While the genus " ___MASK56___ " retains forelimbs , all other genera are limbless . Although superficially similar to the snakes and Dibamidae , recent phylogenetic studies suggest that they are most closely related to the Lacertidae . Amphisbaenians are widely distributed , occurring in North America , Europe , Africa , South America , and the Caribbean . Most species are less than long . Little is known of them outside of their anatomy , and even that is difficult to study due to the mechanics of dissecting such small animals . ___MASK23___ ( Greek for ' ruling lizards ', and Latin for ' form ') is a clade of diapsid reptiles that developed from archosauromorph ancestors some time in the Late Permian ( roughly 250 million years ago ). It was defined by Jacques Gauthier ( 1994 ) as the clade stemming from the last common ancestor of Proterosuchidae and Archosauria ; Phil Senter ( 2005 ) defined it as the most exclusive clade containing " Proterosuchus " and Archosauria . These reptiles , which include members of the family Proterosuchidae and more advanced forms , were originally superficially crocodile - like predatory semi - aquatic animals about 1 . 5 meters ( 5 ft ) long , with a sprawling elbows - out stance and long snouts . Unlike the bulk of their therapsid contemporaries , the proterosuchids survived the catastrophe at the end of the Permian , perhaps because they were opportunistic scavengers or because they could retreat into water to find respite from an overheated climate . Any such scenarios are hypothetical ; what is clearer is that these animals were highly successful in their new environment , and evolved quickly . Within a few million years at the opening of the Triassic , the proterosuchids had given rise to the Erythrosuchidae ( the first sauropsids to totally dominate their environment ), which in turn were the ancestors of the small agile Euparkeriidae , from which a number of successfully more advanced families  the archosaurs proper  evolved rapidly to fill empty ecological niches in the devastated global system . The Archosauria includes crocodylians , birds , and their extinct relatives . Lizards are a widespread group of squamate reptiles , with over 6 , 000 species , ranging across all continents except Antarctica , as well as most oceanic island chains . The group , traditionally recognized as the suborder Lacertilia , is defined as all extant members of the ___MASK88___ ( reptiles with overlapping scales ) that are neither sphenodonts ( i . e ., tuatara ) nor snakes  they form an evolutionary grade . While the snakes are recognized as falling phylogenetically within the ___MASK30___ clade from which they evolved , the sphenodonts are the sister group to the squamates , the larger monophyletic group , which includes both the lizards and the snakes . The superclass ___MASK53___ ( Ancient Greek s tetrapods , " four - footed "), or the tetrapods , comprises the first four - limbed vertebrates and their descendants , including the living and extinct amphibians , birds , mammals , reptiles and some ancient , exclusively aquatic creatures such as the Acanthostega . Tetrapods evolved from the lobe - finned fishes around 390 million years ago in the middle Devonian Period , with modern tetrapod groups having appeared by the late Devonian , 367 . 5 million years ago . The specific aquatic ancestors of the tetrapods , and the process by which land colonization occurred , remain unclear , and are areas of active research and debate among palaeontologists at present . The Jurassic ( from Jura Mountains ) is a geologic period and system that spans 56 . 3 million years from the end of the Triassic Period million years ago ( ___MASK77___ ) to the beginning of the Cretaceous Period ___MASK77___ . The Jurassic constitutes the middle period of the Mesozoic Era , also known as the Age of Reptiles . The start of the period is marked by the major Triassic  Jurassic extinction event . Two other extinction events occurred during the period : the Pliensbachian / Toarcian event in the Early Jurassic , and the Tithonian event at the end ; however , neither event ranks among the " Big Five " mass extinctions . Reptiles are tetrapod ( four - limbed vertebrate ) animals in the class Reptilia , comprising today ' s turtles , crocodilians , snakes , amphisbaenians , lizards , tuatara , and their extinct relatives . The study of these traditional ___MASK13___ orders , historically combined with that of modern amphibians , is called herpetology . The International Code of Nomenclature for algae , ___MASK60___ , and plants ( ICN ) is the set of rules and recommendations dealing with the formal botanical names that are given to plants , ___MASK60___ and a few other groups of organisms , all those " traditionally treated as algae , ___MASK60___ , or plants ". It was formerly called the International Code of Botanical Nomenclature ( ICBN ); the name was changed at the International Botanical Congress in Melbourne in July 2011 as part of the " Melbourne Code " which replaces the " Vienna Code " of 2005 . As with previous codes , it took effect as soon as it was ratified by the congress ( on Saturday 23 July 2011 ), but the documentation of the code in its final form was not finished until some time after the congressional meeting . Preliminary wording of some of the articles with the most significant changes has been published in September 2011 . ___MASK97___ is an early , possibly paraphyletic , assemblage of basal ___MASK23___ whose fossils are known from the Latest Permian and the Early Triassic of Europe , Asia , Africa , Australia and possibly South America . The name comes from Greek  - (" first ") and  (" crocodile "). In biology , an organism is any contiguous living system , such as an ___MASK81___ , ___MASK21___ , fungus , archaeon , or bacterium . All known types of organisms are capable of some degree of response to stimuli , reproduction , growth and development and homeostasis . An organism consists of one or more cells ; when it has one cell it is known as a unicellular organism ; and when it has more than one it is known as a multicellular organism . Most unicellular organisms are of microscopic scale and are thus loosely described as microorganisms . Humans are multicellular organisms composed of many trillions of cells grouped into specialized tissues and organs . Russia is not proportionately populated between the smaller western portion ( almost 25 %) of the country that is considered part of Europe , and the larger eastern portion ( more than 75 %) that is part of Asia . European Russia contains about 77 % of the country ' s population ( 110 , 000 , 000 people out of about 144 , 000 , 000 ) in an ___MASK42___ comprising almost 4 million km ( 1 . 54 million mi ); an average of 27 . 5 persons per km ( 70 per mi ). This territory makes up 38 % of Europe . Its eastern border is defined by the Ural Mountains and in the south , it is defined by the border with Kazakhstan . This ___MASK42___ includes Moscow and Saint Petersburg , the two largest cities in Russia . A holotype is a single physical example ( or illustration ) of an organism , known to have been used when the species ( or lower - ranked taxon ) was formally described . It is either the single such physical example ( or illustration ) or one of several such , but explicitly designated as the holotype . Under the International Code of Zoological Nomenclature ( ICZN ), a holotype is one of several kinds of name - bearing types . In the International Code of Nomenclature for algae , ___MASK60___ , and plants ( ICN ) and ICZN the definitions of types are similar in intent but not identical in terminology or underlying concept . Amphibians are ectothermic , tetrapod vertebrates of the class ___MASK28___ . Modern amphibians are all Lissamphibia . They inhabit a wide variety of habitats , with most species living within terrestrial , fossorial , arboreal or freshwater aquatic ecosystems . Thus amphibians typically start out as larvae living in water , but some species have developed behavioural adaptations to bypass this . The young generally undergo metamorphosis from larva with gills to an adult air - breathing form with lungs . Amphibians use their skin as a secondary respiratory surface and some small terrestrial salamanders and frogs lack lungs and rely entirely on their skin . They are superficially similar to lizards but , along with mammals and birds , reptiles are amniotes and do not require water bodies in which to breed . With their complex reproductive needs and permeable skins , amphibians are often ecological indicators ; in recent decades there has been a dramatic decline in amphibian populations for many species around the globe . Russia ( from the  Rus '), also officially known as the Russian Federation , is a country in Eurasia . At , Russia is the largest country in the world by surface ___MASK42___ , covering more than one - eighth of the Earth ' s inhabited land ___MASK42___ , and the ninth most populous , with over 140 million people at the end of March 2016 . The European western part of the country is much more populated and urbanised than the eastern , about 77 % of the population live in European Russia . Russia ' s capital Moscow is one of the largest cities in the world , other major urban centers include Saint Petersburg , Novosibirsk , Yekaterinburg , Nizhny Novgorod and Samara . Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in central - western Europe . It includes 16 constituent states , covers an ___MASK42___ of , and has a largely temperate seasonal climate . With about 82 million inhabitants , Germany is the most populous member state of the European Union . After the United States , it is the second most popular immigration destination in the world . Germany ' s capital and largest metropolis is Berlin . Other major cities include Hamburg , Munich , Cologne , Frankfurt , Stuttgart and Düsseldorf . Novosibirsk is the third - most populous city in Russia after Moscow and St . Petersburg . It is the most populous city in Asian Russia , with a population of 1 , 473 , 754 as of the 2010 Census . It is the administrative center of Novosibirsk Oblast as well as of the Siberian Federal District . The city is located in the southwestern part of Siberia on the banks of the Ob River adjacent to the Ob River Valley , near the large water reservoir formed by the dam of the Novosibirsk Hydro Power ___MASK21___ , and occupies an area of . Sarmatosuchus is an extinct genus of archosauriform ___MASK13___ found in sediments of early Triassic age and know from the single species Sarmatosuchus otschevi . The holotype and only specimen was found in litified river deposits of the Donguz Formation exposed near the Berdyanka River , Orenburg region , Russia . The genus was originally included in the extinct family Proterosuchidae . However later analysis by David Gower and Andrei Sennikov , the describing author , has removed it from the Proterosuchidae and designated it a basal archosaur . Binomial nomenclature ( also called binominal nomenclature or binary nomenclature ) is a formal system of naming species of living things by giving each a name composed of two parts , both of which use Latin grammatical forms , although they can be based on words from other languages . Such a name is called a binomial name ( which may be shortened to just " binomial "), a binomen or a scientific name ; more informally it is also called a Latin name . The first part of the name identifies the genus to which the species belongs ; the second part identifies the species within the genus . For example , humans belong to the genus " ___MASK57___ " and within this genus to the species " ___MASK57___ sapiens ". The " formal " introduction of this system of naming species is credited to Carl Linnaeus , effectively beginning with his work " Species Plantarum " in 1753 . But Gaspard Bauhin , in as early as 1623 , had introduced in his book " Pinax theatri botanici " ( English , " Illustrated exposition of plants ") many names of genera that were later adopted by Linnaeus . Tuatara are reptiles endemic to New Zealand . Although resembling most lizards , they are part of a distinct lineage , the order ___MASK64___ . Their name derives from the Mori language , and means " peaks on the back ". The single species of tuatara is the only surviving member of its order , which flourished around 200 million years ago . Their most recent common ancestor with any other extant group is with the squamates ( lizards and snakes ). For this reason , tuatara are of great interest in the study of the evolution of lizards and snakes , and for the reconstruction of the appearance and habits of the earliest diapsids , a group of amniote tetrapods that also includes dinosaurs , birds , and crocodilians . The ___MASK95___ ( or Crocodylia ) are an order of mostly large , predatory , semiaquatic reptiles . They appeared 83 . 5 million years ago in the Late Cretaceous period ( Campanian stage ) and are the closest living relatives of birds , as the two groups are the only known survivors of the Archosauria . Members of the order ' s total group , the clade ___MASK45___ , appeared about 250 million years ago in the Early Triassic period , and diversified during the Mesozoic era . The order ___MASK95___ includes the true crocodiles ( family Crocodylidae ), the alligators and caimans ( family Alligatoridae ), and the gharial and false gharial ( family ___MASK61___ ). Although the term ' crocodiles ' is sometimes used to refer to all of these , a less ambiguous vernacular term for this group is crocodilians . Herpetology ( from Greek "" herpein "" meaning " to creep ") is the branch of zoology concerned with the study of amphibians ( including frogs , toads , salamanders , newts , and caecilians ( ___MASK80___ )) and reptiles ( including snakes , lizards , amphisbaenids , turtles , terrapins , tortoises , crocodilians , and the tuataras ). Batrachology is a further subdiscipline of herpetology concerned with the study of amphibians alone .