The Yixian Formation ( simplified Chinese : 义县组 ; traditional Chinese : 義縣組 ; pinyin : Yìxiàn zǔ ; formerly transcribed as Yihsien Formation ) is a geological formation in Jinzhou , Liaoning , People's Republic of China , that spans the Barremian stage of the Early Cretaceous. It is known for its exquisitely preserved fossils , and is mainly composed of basalts interspersed with siliciclastic sediments.
168-683: The potential importance of the Yixian Formation was initially recognized during the time the Empire of Japan occupied China's Rehe ("Jehol") Province after the Defense of the Great Wall in 1933. Many Japanese scientists had noticed fossil remains of extinct fish and reptiles, possibly the champsosaurs . These initial fossil discoveries made by Japanese scientists vanished once World War II ended in 1945. By 1949, when administration of
336-624: A gazetteer compiled by Chang Qu ( 常璩 ) during the Western Jin Dynasty (265–316), reported the discovery of dragon bones at Wucheng in Sichuan Province. Villagers in central China have long unearthed fossilized "dragon bones" for use in traditional medicines . In Europe , dinosaur fossils were generally believed to be the remains of giants and other biblical creatures. Scholarly descriptions of what would now be recognized as dinosaur bones first appeared in
504-523: A sacrum composed of three or more fused vertebrae (three are found in some other archosaurs, but only two are found in Herrerasaurus ); and a perforate acetabulum , or hip socket, with a hole at the center of its inside surface (closed in Saturnalia tupiniquim , for example). Another difficulty of determining distinctly dinosaurian features is that early dinosaurs and other archosaurs from
672-599: A tributary state of China's Qing Empire , which exerted large influence over the conservative Korean officials who gathered around the royal family of the Joseon kingdom. On February 27, 1876, after several confrontations between Korean isolationists and the Japanese, Japan imposed the Japan–Korea Treaty of 1876 , forcing Korea open to Japanese trade. The act blocked any other power from dominating Korea, resolving to end
840-421: A "pillar-erect" configuration of the hip joint, where instead of having a projection from the femur insert on a socket on the hip, the upper pelvic bone was rotated to form an overhanging shelf. Dinosaur fossils have been known for millennia, although their true nature was not recognized. The Chinese considered them to be dragon bones and documented them as such. For example, Huayang Guo Zhi ( 華陽國志 ),
1008-649: A Theory of Civilization", which detailed Western society and his own philosophies. In the Meiji Restoration period, military and economic power was emphasized. Military strength became the means for national development and stability. Imperial Japan became the only non-Western world power and a major force in East Asia in about 25 years as a result of industrialization and economic development. As writer Albrecht Fürst von Urach comments in his booklet "The Secret of Japan's Strength", published in 1942, during
1176-613: A chapel of the Russian Consulate. St. Nicholas of Japan made his own translation of the New Testament and some other religious books ( Lenten Triodion , Pentecostarion , Feast Services , Book of Psalms , Irmologion ) into Japanese . Nicholas has since been canonized as a saint by the Patriarchate of Moscow in 1970, and is now recognized as St. Nicholas, Equal-to-the-Apostles to Japan. His commemoration day
1344-557: A conservative list is give here, from most recent to oldest: (ages when available from Zhong et al. , 2021) The Yixian Formation represents the second of three major faunal phases that characterize the Jehol Biota , mainly based on changes in invertebrate diversity. In the Yixian, ostracods (seed shrimp) had diversified considerably, despite a very low diversity in the earlier Dabeigou Formation . Other major invertebrate groups in
1512-639: A continued collaboration with the Tokugawa, Saigō Takamori , leader of the Satsuma clan, threatened the assembly into abolishing the title shōgun and ordered the confiscation of Yoshinobu's lands. On January 17, 1868, Yoshinobu declared "that he would not be bound by the proclamation of the Restoration and called on the court to rescind it". On January 24, Yoshinobu decided to prepare an attack on Kyoto, occupied by Satsuma and Chōshū forces. This decision
1680-488: A controversial taxon that was recently confirmed to exist after archived photos were uncovered. Bruhathkayosaurus was a titanosaur and would have most likely weighed more than even Marrapunisaurus . Recent size estimates in 2023 have placed this sauropod reaching lengths of up to 44 m (144 ft) long and a colossal weight range of around 110 000 – 170 000 kg ( 240 000 – 370 000 lb), if these upper estimates up true, Bruhathkayosaurus would have rivaled
1848-448: A corresponding inwardly facing distinct head on the femur. Their erect posture enabled early dinosaurs to breathe easily while moving, which likely permitted stamina and activity levels that surpassed those of "sprawling" reptiles . Erect limbs probably also helped support the evolution of large size by reducing bending stresses on limbs. Some non-dinosaurian archosaurs, including rauisuchians , also had erect limbs but achieved this by
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#17327729724892016-658: A debate over defining the political system of Japan as a dictatorship . The Imperial Japanese Armed Forces initially achieved large-scale military successes during the Second Sino-Japanese War and the Pacific War . However, from 1942 onwards, and particularly after decisive Allied advances at Midway Atoll and Guadalcanal , Japan was forced to adopt a defensive stance against the United States . The American-led island-hopping campaign led to
2184-652: A dinosaur. In it he described and named a sauropod tooth , " Rutellum impicatum ", that had been found in Caswell, near Witney , Oxfordshire. Between 1815 and 1824, the Rev William Buckland , the first Reader of Geology at the University of Oxford, collected more fossilized bones of Megalosaurus and became the first person to describe a non-avian dinosaur in a scientific journal . The second non-avian dinosaur genus to be identified, Iguanodon ,
2352-537: A femur of Tyrannosaurus preserved soft, flexible tissue within, including blood vessels , bone matrix , and connective tissue (bone fibers) that had retained their microscopic structure. This discovery suggested that original soft tissues could be preserved over geological time, with multiple mechanisms having been proposed. Later, in 2009, Schweitzer and colleagues reported that a Brachylophosaurus femur preserved similar microstructures, and immunohistochemical techniques (based on antibody binding) demonstrated
2520-487: A generally humid climate. However, evidence from the growth rings of petrified wood indicates that the humidity and water supply dropped regularly. This shows that the wet, humid conditions were punctuated by dry seasons, in which the environment became more arid. Evidence from the study of oxygen isotopes has shown that the average yearly temperature during this time period was 10 degrees celsius (50 degrees Fahrenheit ), significantly colder than once thought. This indicates
2688-422: A group known as archosaurs, which also includes modern crocodilians. Within the archosaur group, dinosaurs are differentiated most noticeably by their gait. Dinosaur legs extend directly beneath the body, whereas the legs of lizards and crocodilians sprawl out to either side. Collectively, dinosaurs as a clade are divided into two primary branches, Saurischia and Ornithischia. Saurischia includes those taxa sharing
2856-486: A more recent common ancestor with birds than with Ornithischia, while Ornithischia includes all taxa sharing a more recent common ancestor with Triceratops than with Saurischia. Anatomically, these two groups can be distinguished most noticeably by their pelvic structure. Early saurischians—"lizard-hipped", from the Greek sauros ( σαῦρος ) meaning "lizard" and ischion ( ἰσχίον ) meaning "hip joint"—retained
3024-583: A now lost partial vertebral neural arch described in 1878. Extrapolating from the illustration of this bone, the animal may have been 58 meters (190 ft) long and weighed 122 400 kg ( 269 800 lb). However, recent research have placed Amphicoelias from the long, gracile diplodocid to the shorter but much stockier rebbachisaurid. Now renamed as Maraapunisaurus , this sauropod now stands as much as 40 meters (130 ft) long and weigh as much as 120 000 kg ( 260 000 lb). Another contender of this title includes Bruhathkayosaurus ,
3192-433: A period of time, with estimates ranging from 5–10 million years to 21 million years. When dinosaurs appeared, they were not the dominant terrestrial animals. The terrestrial habitats were occupied by various types of archosauromorphs and therapsids , like cynodonts and rhynchosaurs . Their main competitors were the pseudosuchians , such as aetosaurs , ornithosuchids and rauisuchians, which were more successful than
3360-663: A potential food source, radiated in the Late Triassic. Early sauropodomorphs did not have sophisticated mechanisms for processing food in the mouth, and so must have employed other means of breaking down food farther along the digestive tract. The general homogeneity of dinosaurian faunas continued into the Middle and Late Jurassic, where most localities had predators consisting of ceratosaurians , megalosauroids , and allosauroids , and herbivores consisting of stegosaurian ornithischians and large sauropods. Examples of this include
3528-681: A presentation about fossil reptiles to the British Association for the Advancement of Science in 1841, but reports of the time show that Owen did not mention the word "dinosaur", nor recognize dinosaurs as a distinct group of reptiles in his address. He introduced the Dinosauria only in the revised text version of his talk published in April 1842. With the backing of Prince Albert , the husband of Queen Victoria , Owen established
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#17327729724893696-454: A prospect hard-liners from Satsuma and Chōshū found intolerable. On January 3, 1868, Satsuma-Chōshū forces seized the imperial palace in Kyoto , and the following day had the fifteen-year-old Emperor Meiji declare his own restoration to full power. Although the majority of the imperial consultative assembly was happy with the formal declaration of direct rule by the court and tended to support
3864-599: A review paper by Paul Sereno in 1998, were accompanied by increases in the number of published phylogenetic trees for dinosaurs. Dinosaur fossils are not limited to bones, but also include imprints or mineralized remains of skin coverings, organs, and other tissues. Of these, skin coverings based on keratin proteins are most easily preserved because of their cross-linked , hydrophobic molecular structure. Fossils of keratin-based skin coverings or bony skin coverings are known from most major groups of dinosaurs. Dinosaur fossils with scaly skin impressions have been found since
4032-419: A series of freshwater lakes , provided with abundant minerals thanks to periodic volcanic eruptions . Volcanic activity, along with periodic wildfires , and noxious gasses released from the lake bottoms caused the ecosystem to be continually destroyed and regrown. This, along with the wide diversity of habitats in the surrounding region, may have contributed to the fast diversification of life forms present in
4200-549: A series of studies that likewise argued for active lifestyles in dinosaurs based on anatomical and ecological evidence (see § Physiology ), which were subsequently summarized in his 1986 book The Dinosaur Heresies . New revelations were supported by an increase in dinosaur discoveries. Major new dinosaur discoveries have been made by paleontologists working in previously unexplored regions, including India, South America, Madagascar, Antarctica, and most significantly China. Across theropods, sauropodomorphs, and ornithischians,
4368-603: A sister group to Dinosauria, including a large anterior trochanter, metatarsals II and IV of subequal length, reduced contact between ischium and pubis, the presence of a cnemial crest on the tibia and of an ascending process on the astragalus, and many others. A variety of other skeletal features are shared by dinosaurs. However, because they either are common to other groups of archosaurs or were not present in all early dinosaurs, these features are not considered to be synapomorphies. For example, as diapsids , dinosaurs ancestrally had two pairs of Infratemporal fenestrae (openings in
4536-465: A temperate climate with unusually cold winters for the generally warm Mesozoic era, possibly due to northern China's high latitude during this time. A study by Wu et al. (2013) concluded that orbital forcing , which is the effect on climate caused by shifts in the tilt of the Earth's axis and by the shape of the Earth's orbit, contributed to the climate fluctuations of this formation. The Yixian Formation
4704-490: A universally agreed-upon list of their distinguishing features, nearly all dinosaurs discovered so far share certain modifications to the ancestral archosaurian skeleton, or are clearly descendants of older dinosaurs showing these modifications. Although some later groups of dinosaurs featured further modified versions of these traits, they are considered typical for Dinosauria; the earliest dinosaurs had them and passed them on to their descendants. Such modifications, originating in
4872-433: A variety of horsetails that closely resembled modern species. It is possible that increasing animal and plant diversity were linked. The Yixian is characterized by extensive forests, dominated by trees such as ginkgoes , conifers , cycads , and seed fern trees. Ground cover plants included lycopods , horsetails, ferns , and primitive flowering plants, which were rare compared to the others. This plant life grew around
5040-468: A variety of waterbirds , diversified rapidly at the beginning of the Paleogene period, entering ecological niches left vacant by the extinction of Mesozoic dinosaur groups such as the arboreal enantiornithines , aquatic hesperornithines , and even the larger terrestrial theropods (in the form of Gastornis , eogruiids , bathornithids , ratites, geranoidids , mihirungs , and " terror birds "). It
5208-449: A variety of fields to come to Japan to educate the populace. For instance, the judicial system and constitution were modeled after Prussia , described by Saburō Ienaga as "an attempt to control popular thought with a blend of Confucianism and German conservatism ." The government also outlawed customs linked to Japan's feudal past, such as publicly displaying and wearing katana and the top knot , both of which were characteristic of
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5376-430: Is 39.7 meters (130 ft) long. There were larger dinosaurs, but knowledge of them is based entirely on a small number of fragmentary fossils. Most of the largest herbivorous specimens on record were discovered in the 1970s or later, and include the massive Argentinosaurus , which may have weighed 80 000 to 100 000 kilograms (88 to 110 short tons) and reached lengths of 30 to 40 meters (98 to 131 ft); some of
5544-547: Is February 16. Andronic Nikolsky , appointed the first Bishop of Kyoto and later martyred as the archbishop of Perm during the Russian Revolution , was also canonized by the Russian Orthodox Church as a Saint and Martyr in the year 2000. Divie Bethune McCartee was the first ordained Presbyterian minister missionary to visit Japan, in 1861–1862. His gospel tract translated into Japanese
5712-710: Is a synapsid ). None of them had the erect hind limb posture characteristic of true dinosaurs. Dinosaurs were the dominant terrestrial vertebrates of the Mesozoic Era , especially the Jurassic and Cretaceous periods. Other groups of animals were restricted in size and niches; mammals , for example, rarely exceeded the size of a domestic cat and were generally rodent-sized carnivores of small prey. Dinosaurs have always been recognized as an extremely varied group: over 900 non-avian dinosaur genera have been confidently identified (2018) with 1124 species (2016). Estimates put
5880-470: Is an inexact art, and reconstructing the muscles and other organs of the living animal is, at best, a process of educated guesswork. The tallest and heaviest dinosaur known from good skeletons is Giraffatitan brancai (previously classified as a species of Brachiosaurus ). Its remains were discovered in Tanzania between 1907 and 1912. Bones from several similar-sized individuals were incorporated into
6048-755: Is based in part on preservation bias , as large, sturdy bones are more likely to last until they are fossilized. Many dinosaurs were quite small, some measuring about 50 centimeters (20 inches) in length. The first dinosaur fossils were recognized in the early 19th century, with the name "dinosaur" (meaning "terrible lizard") being coined by Sir Richard Owen in 1842 to refer to these "great fossil lizards". Since then, mounted fossil dinosaur skeletons have been major attractions at museums worldwide, and dinosaurs have become an enduring part of popular culture . The large sizes of some dinosaurs, as well as their seemingly monstrous and fantastic nature, have ensured their regular appearance in best-selling books and films, such as
6216-466: Is between 1 and 10 metric tons (1.1 and 11.0 short tons). This contrasts sharply with the average size of Cenozoic mammals, estimated by the National Museum of Natural History as about 2 to 5 kg (4.4 to 11.0 lb). The sauropods were the largest and heaviest dinosaurs. For much of the dinosaur era, the smallest sauropods were larger than anything else in their habitat, and the largest
6384-526: Is currently better known as the Kaihōrei ( 解放令 Emancipation Edict ). However, the elimination of their economic monopolies over certain occupations actually led to a decline in their general living standards, while social discrimination simply continued. For example, the ban on the consumption of meat from livestock was lifted in 1871, and many former burakumin moved on to work in abattoirs and as butchers . However, slow-changing social attitudes, especially in
6552-621: Is derived from a variety of fossil and non-fossil records, including fossilized bones, feces , trackways , gastroliths , feathers , impressions of skin, internal organs and other soft tissues . Many fields of study contribute to our understanding of dinosaurs, including physics (especially biomechanics ), chemistry , biology , and the Earth sciences (of which paleontology is a sub-discipline). Two topics of particular interest and study have been dinosaur size and behavior. Current evidence suggests that dinosaur average size varied through
6720-515: Is frequently referred to as the "Empire of Japan", the "Japanese Empire", or "Imperial Japan" in English. In Japanese it is referred to as Dai Nippon Teikoku ( 大日本帝國 ) , which translates to "Empire of Great Japan" ( Dai "Great", Nippon "Japanese", Teikoku "Empire"). Teikoku is itself composed of the nouns Tei "referring to an emperor" and -koku "nation, state", literally "Imperial State" or "Imperial Realm" (compare
6888-591: Is now at the American Museum of Natural History in New York City, while Marsh's is at the Peabody Museum of Natural History at Yale University . World War II caused a pause in palaeontological research; after the war, research attention was also diverted increasingly to fossil mammals rather than dinosaurs, which were seen as sluggish and cold-blooded. At the end of the 1960s, however,
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7056-654: Is often stated that mammals out-competed the neornithines for dominance of most terrestrial niches but many of these groups co-existed with rich mammalian faunas for most of the Cenozoic Era. Terror birds and bathornithids occupied carnivorous guilds alongside predatory mammals, and ratites are still fairly successful as midsized herbivores; eogruiids similarly lasted from the Eocene to Pliocene , becoming extinct only very recently after over 20 million years of co-existence with many mammal groups. Dinosaurs belong to
7224-401: Is well known for its great diversity of well-preserved specimens and its feathered dinosaurs, such as the large tyrannosauroid Yutyrannus , the therizinosaur Beipiaosaurus , and various small birds, along with a selection of other dinosaurs, such as the iguanodontian Bolong , the sauropod Dongbeititan and the ceratopsian Psittacosaurus . Other biota included the troodontid Mei ,
7392-535: The Jurassic Park franchise. Persistent public enthusiasm for the animals has resulted in significant funding for dinosaur science, and new discoveries are regularly covered by the media. Under phylogenetic nomenclature , dinosaurs are usually defined as the group consisting of the most recent common ancestor (MRCA) of Triceratops and modern birds (Neornithes), and all its descendants. It has also been suggested that Dinosauria be defined with respect to
7560-437: The blue whale and Perucetus colossus as one of the largest animals to have ever existed. The largest carnivorous dinosaur was Spinosaurus , reaching a length of 12.6 to 18 meters (41 to 59 ft) and weighing 7 to 20.9 metric tons (7.7 to 23.0 short tons). Other large carnivorous theropods included Giganotosaurus , Carcharodontosaurus , and Tyrannosaurus . Therizinosaurus and Deinocheirus were among
7728-695: The Anisian epoch of the Triassic, approximately 243 million years ago, which is the age of Nyasasaurus from the Manda Formation of Tanzania. However, its known fossils are too fragmentary to identify it as a dinosaur or only a close relative. The referral of the Manda Formation to the Anisian is also uncertain. Regardless, dinosaurs existed alongside non-dinosaurian ornithodirans for
7896-637: The Axis powers period: The rise of Japan to a world power during the past 80 years is the greatest miracle in world history. The mighty empires of antiquity, the major political institutions of the Middle Ages and the early modern era, the Spanish Empire, the British Empire, all needed centuries to achieve their full strength. Japan's rise has been meteoric. After only 80 years, it is one of
8064-462: The Carnian pluvial event . Dinosaur evolution after the Triassic followed changes in vegetation and the location of continents. In the Late Triassic and Early Jurassic, the continents were connected as the single landmass Pangaea , and there was a worldwide dinosaur fauna mostly composed of coelophysoid carnivores and early sauropodomorph herbivores. Gymnosperm plants (particularly conifers ),
8232-728: The Emperor from the Shogun , Japan underwent a period of large-scale industrialization and militarization , often regarded as the fastest modernization of any country to date. All of these aspects contributed to Japan's emergence as a great power following the First Sino-Japanese War , the Boxer Rebellion , the Russo-Japanese War , and World War I . Economic and political turmoil in the 1920s, including
8400-572: The German Kaiserreich ). The name "Empire of Japan" appeared for the first time in the 1854 Convention of Kanagawa between the United States and the Japanese Tokugawa shogunate . This meaning is significant in terms of geography, encompassing Japan, and its surrounding areas. The nomenclature Empire of Japan had existed since the anti-Tokugawa domains, Satsuma and Chōshū , which founded their new government during
8568-703: The Great Depression , led to the rise of militarism , nationalism , statism and authoritarianism, and this ideological shift eventually culminated in Japan joining the Axis alliance with Nazi Germany and Fascist Italy , and also conquering a large part of the Asia-Pacific . During this period, the Japanese army committed many atrocities, including the Nanjing Massacre . However, there has been
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#17327729724898736-637: The Ischigualasto and Santa Maria Formations of Argentina and Brazil, and the Pebbly Arkose Formation of Zimbabwe. The Ischigualasto Formation ( radiometrically dated at 231–230 million years old ) has produced the early saurischian Eoraptor , originally considered a member of the Herrerasauridae but now considered to be an early sauropodomorph, along with the herrerasaurids Herrerasaurus and Sanjuansaurus , and
8904-491: The Late Triassic epoch are often poorly known and were similar in many ways; these animals have sometimes been misidentified in the literature. Dinosaurs stand with their hind limbs erect in a manner similar to most modern mammals , but distinct from most other reptiles, whose limbs sprawl out to either side. This posture is due to the development of a laterally facing recess in the pelvis (usually an open socket) and
9072-697: The Meiji Restoration , with the intention of forming a modern state to resist Western domination. Later the Empire emerged as a great power in the world. Due to its name in kanji characters and its flag, it was also given the exonyms "Empire of the Sun" and "Empire of the Rising Sun". After two centuries, the seclusion policy, or sakoku , under the shōguns of the Edo period came to an end when
9240-682: The Meiji period , affecting religious practices and institutions. Conversion from traditional faith was no longer legally forbidden, officials lifted the 250-year ban on Christianity, and missionaries of established Christian churches reentered Japan. The traditional syncreticism between Shinto and Buddhism ended. Losing the protection of the Japanese government which Buddhism had enjoyed for centuries, Buddhist monks faced radical difficulties in sustaining their institutions, but their activities also became less restrained by governmental policies and restrictions. As social conflicts emerged in this last decade of
9408-657: The Morrison Formation of North America and Tendaguru Beds of Tanzania. Dinosaurs in China show some differences, with specialized metriacanthosaurid theropods and unusual, long-necked sauropods like Mamenchisaurus . Ankylosaurians and ornithopods were also becoming more common, but primitive sauropodomorphs had become extinct. Conifers and pteridophytes were the most common plants. Sauropods, like earlier sauropodomorphs, were not oral processors, but ornithischians were evolving various means of dealing with food in
9576-497: The Natural History Museum, London , to display the national collection of dinosaur fossils and other biological and geological exhibits. In 1858, William Parker Foulke discovered the first known American dinosaur, in marl pits in the small town of Haddonfield, New Jersey . (Although fossils had been found before, their nature had not been correctly discerned.) The creature was named Hadrosaurus foulkii . It
9744-621: The Pietraroja Plattenkalk of Italy. It preserves portions of the intestines, colon, liver, muscles, and windpipe. Concurrently, a line of work led by Mary Higby Schweitzer , Jack Horner , and colleagues reported various occurrences of preserved soft tissues and proteins within dinosaur bone fossils. Various mineralized structures that likely represented red blood cells and collagen fibres had been found by Schweitzer and others in tyrannosaurid bones as early as 1991. However, in 2005, Schweitzer and colleagues reported that
9912-804: The Shrine Consolidation Policy and the Meiji government built the new modern 15 shrines of the Kenmu restoration as a political move to link the Meiji restoration to the Kenmu restoration for their new State Shinto cult. Japanese had to look at old paintings in order to find out what the Horyuji temple used to look like when they rebuilt it. The rebuilding was originally planned for the Shōwa era. The Japanese used mostly concrete in 1934 to rebuild
10080-529: The Togetsukyo Bridge , unlike the original destroyed wooden version of the bridge from 836. The idea of a written constitution had been a subject of heated debate within and outside of the government since the beginnings of the Meiji government . The conservative Meiji oligarchy viewed anything resembling democracy or republicanism with suspicion and trepidation, and favored a gradualist approach. The Freedom and People's Rights Movement demanded
10248-646: The United States and displayed in Pittsburgh 's Carnegie Museum of Natural History in 1907. The longest dinosaur known from good fossil material is Patagotitan : the skeleton mount in the American Museum of Natural History in New York is 37 meters (121 ft) long. The Museo Municipal Carmen Funes in Plaza Huincul , Argentina, has an Argentinosaurus reconstructed skeleton mount that
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#173277297248910416-509: The bombardment of Shimonoseki by a multinational force in 1864. The Chōshū clan also launched the failed coup known as the Kinmon incident . The Satsuma-Chōshū alliance was established in 1866 to combine their efforts to overthrow the Tokugawa bakufu . In early 1867, Emperor Kōmei died of smallpox and was replaced by his son, Crown Prince Mutsuhito (Meiji) . On November 9, 1867, Tokugawa Yoshinobu resigned from his post and authorities to
10584-427: The largest and smallest dinosaurs to have ever existed. This is because only a tiny percentage of animals were ever fossilized and most of these remain buried in the earth. Few non-avian dinosaur specimens that are recovered are complete skeletons, and impressions of skin and other soft tissues are rare. Rebuilding a complete skeleton by comparing the size and morphology of bones to those of similar, better-known species
10752-482: The "lizard-hipped" dinosaurs—birds evolved from earlier dinosaurs with "lizard hips". The following is a simplified classification of dinosaur groups based on their evolutionary relationships, and those of the main dinosaur groups Theropoda, Sauropodomorpha and Ornithischia, compiled by Justin Tweet. Further details and other hypotheses of classification may be found on individual articles. Timeline of major dinosaur groups per Holtz (2007) . Knowledge about dinosaurs
10920-409: The 19th century. Samuel Beckles discovered a sauropod forelimb with preserved skin in 1852 that was incorrectly attributed to a crocodile; it was correctly attributed by Marsh in 1888 and subject to further study by Reginald Hooley in 1917. Among ornithischians, in 1884 Jacob Wortman found skin impressions on the first known specimen of Edmontosaurus annectens , which were largely destroyed during
11088-411: The British commander. The force landed near Tianjin on July 5. On 17 June 1900, naval Rikusentai from the Kasagi and Atago had joined British, Russian, and German sailors to seize the Dagu forts near Tianjin. In light of the precarious situation, the British were compelled to ask Japan for additional reinforcements, as the Japanese had the only readily available forces in the region. Britain at
11256-418: The Chaomidianzi Formation is disused as a synonym for the Jianshangou Bed of the Yixian Formation. The Dabeigou Formation in Fengning, Hebei Province may immediately precede the Yixian, or it may be equivalent to the oldest Yixian beds. The Yixian also overlies the Tuchengzi Formation in places. The Yixian Formation is informally divided into several subunits and the stratigraphy remains controversial so
11424-421: The Chinese forces on the Liaodong Peninsula , and nearly destroyed the Chinese navy in the Battle of the Yalu River . The Treaty of Shimonoseki was signed between Japan and China, which ceded the Liaodong Peninsula and the island of Taiwan to Japan. After the peace treaty, Russia, Germany, and France forced Japan to withdraw from Liaodong Peninsula in the Triple Intervention . Soon afterward, Russia occupied
11592-605: The Daimyo and Shoguns. It was only due to the 1964 Summer Olympics in Japan that cheap concrete replicas of those castles were built for tourists. The vast majority of castles in Japan today are new replicas made out of concrete. In 1959 a concrete keep was built for Nagoya castle. During the Meiji restoration's Shinbutsu bunri , tens of thousands of Japanese Buddhist religious idols and temples were smashed and destroyed. Many statues still lie in ruins. Replica temples were rebuilt with concrete. Japan then closed and shut done tens of thousands of traditional old Shinto shrines in
11760-429: The Edo period, some new religious movements appeared, which were directly influenced by shamanism and Shinto . Emperor Ogimachi issued edicts to ban Catholicism in 1565 and 1568, but to little effect. Beginning in 1587 with imperial regent Toyotomi Hideyoshi's ban on Jesuit missionaries, Christianity was repressed as a threat to national unity. Under Hideyoshi and the succeeding Tokugawa shogunate, Catholic Christianity
11928-502: The Emperor and his Imperial House, and also against some major Shinto shrines which were believed to be tied strongly to the Emperor. The government strengthened its control over religious institutions that were considered to undermine State Shinto or nationalism. The majority of Japanese castles were smashed and destroyed in the late 19th century in the Meiji restoration by the Japanese people and government in order to modernize and westernize Japan and break from their past feudal era of
12096-456: The English paleontologist Sir Richard Owen coined the term "dinosaur", using it to refer to the "distinct tribe or sub-order of Saurian Reptiles" that were then being recognized in England and around the world. The term is derived from Ancient Greek δεινός (deinos) 'terrible, potent or fearfully great' and σαῦρος (sauros) 'lizard or reptile'. Though
12264-581: The Greek ornitheios (ὀρνίθειος) meaning "of a bird" and ischion (ἰσχίον) meaning "hip joint"—had a pelvis that superficially resembled a bird's pelvis: the pubic bone was oriented caudally (rear-pointing). Unlike birds, the ornithischian pubis also usually had an additional forward-pointing process. Ornithischia includes a variety of species that were primarily herbivores. Despite the terms "bird hip" (Ornithischia) and "lizard hip" (Saurischia), birds are not part of Ornithischia. Birds instead belong to Saurischia,
12432-579: The Heavens and with the Earth, We shall maintain and secure from decline the ancient form of government. ... In consideration of the progressive tendency of the course of human affairs and in parallel with the advance of civilization, We deem it expedient, in order to give clearness and distinctness to the instructions bequeathed by the Imperial Founder of Our House and by Our other Imperial Ancestors, to establish fundamental laws. ... Imperial Japan
12600-466: The Japanese government one million British pounds in exchange for Japanese participation. Dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria . They first appeared during the Triassic period , between 243 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is a subject of active research. They became
12768-679: The Jehol Coal-bearing Beds, the Jehol Oil Shale Beds, and the Jehol Volcanic Rocks. The Yixian Formation is preceded by the older Daohugou Beds , of uncertain Jurassic or Early Cretaceous age, which are sometimes considered part of the Jehol group. The Yixian Formation (including the synonymous Jingangshan, Tuhulu, Jianchang, Lower Volcanic and Volcanic Rock formations) is followed stratigraphically by
12936-637: The Korean government. When Korea demanded that Japan withdraw its troops from Korea, the Japanese refused. In early June 1894, the 8,000 Japanese troops captured the Korean king Gojong, occupied the Royal Palace in Seoul and, by June 25, installed a puppet government in Seoul. The new pro-Japanese Korean government granted Japan the right to expel Qing forces while Japan dispatched more troops to Korea. China objected and war ensued. Japanese ground troops routed
13104-508: The Late Cretaceous, was the evolution of flowering plants . At the same time, several groups of dinosaurian herbivores evolved more sophisticated ways to orally process food. Ceratopsians developed a method of slicing with teeth stacked on each other in batteries, and iguanodontians refined a method of grinding with dental batteries , taken to its extreme in hadrosaurids. Some sauropods also evolved tooth batteries, best exemplified by
13272-840: The Liaodong Peninsula, built the Port Arthur fortress, and based the Russian Pacific Fleet in the port. Germany occupied Jiaozhou Bay , built Tsingtao fortress and based the German East Asia Squadron in this port. In 1900, Japan joined an international military coalition set up in response to the Boxer Rebellion in the Qing Empire of China. Japan provided the largest contingent of troops: 20,840, as well as 18 warships. Of
13440-785: The MRCA of Megalosaurus and Iguanodon , because these were two of the three genera cited by Richard Owen when he recognized the Dinosauria. Both definitions cover the same known genera: Dinosauria = Ornithischia + Saurischia . This includes major groups such as ankylosaurians (armored herbivorous quadrupeds), stegosaurians (plated herbivorous quadrupeds), ceratopsians (bipedal or quadrupedal herbivores with neck frills ), pachycephalosaurians (bipedal herbivores with thick skulls), ornithopods (bipedal or quadrupedal herbivores including " duck-bills "), theropods (mostly bipedal carnivores and birds), and sauropodomorphs (mostly large herbivorous quadrupeds with long necks and tails). Birds are
13608-489: The Meiji Restoration, the practices of the samurai classes, deemed feudal and unsuitable for modern times following the end of sakoku in 1853, resulted in a number of edicts intended to 'modernise' the appearance of upper class Japanese men. With the Dampatsurei Edict of 1871 issued by Emperor Meiji during the early Meiji Era, men of the samurai classes were forced to cut their hair short, effectively abandoning
13776-401: The Middle to Late Triassic epochs, roughly 20 million years after the devastating Permian–Triassic extinction event wiped out an estimated 96% of all marine species and 70% of terrestrial vertebrate species approximately 252 million years ago. The oldest dinosaur fossils known from substantial remains date to the Carnian epoch of the Triassic period and have been found primarily in
13944-547: The Tokugawa army. A series of battles were then fought in pursuit of supporters of the Shogunate; Edo surrendered to the Imperial forces and afterward, Yoshinobu personally surrendered. Yoshinobu was stripped of all his power by Emperor Meiji and most of Japan accepted the emperor's rule. Pro-Tokugawa remnants retreated to northern Honshū ( Ōuetsu Reppan Dōmei ) and later to Ezo (present-day Hokkaidō ), where they established
14112-524: The Triassic, Early Jurassic, Late Jurassic and Cretaceous. Predatory theropod dinosaurs, which occupied most terrestrial carnivore niches during the Mesozoic, most often fall into the 100-to-1,000 kg (220-to-2,200 lb) category when sorted by estimated weight into categories based on order of magnitude , whereas recent predatory carnivoran mammals peak in the 10-to-100 kg (22-to-220 lb) category. The mode of Mesozoic dinosaur body masses
14280-595: The United States, known as dinosaur mania. Dinosaur mania was exemplified by the fierce rivalry between Edward Drinker Cope and Othniel Charles Marsh , both of whom raced to be the first to find new dinosaurs in what came to be known as the Bone Wars . This fight between the two scientists lasted for over 30 years, ending in 1897 when Cope died after spending his entire fortune on the dinosaur hunt. Many valuable dinosaur specimens were damaged or destroyed due to
14448-637: The Western Allies and the Soviet Union , with the atomic bombings of Hiroshima and Nagasaki and the Soviet invasion of Manchuria . The Pacific War officially came to an end on 2 September 1945, leading to the beginning of the Allied occupation of Japan , during which United States military leader Douglas MacArthur administered the country. In 1947, through Allied efforts, a new Japan's constitution
14616-463: The Yixian ecosystem. With the diversity of plant life in the Yixian well known, including examples of a variety of petrified wood and growth rings, and with the help of chemical analysis, scientists have been able to determine the climate of the formation. The Yixian flora was dominated by conifers closely related to modern species that are found mainly in subtropical and temperate upland forests. The presence of ferns, cycads, and horsetails indicates
14784-443: The Yixian include clam shrimp and insects . Insects, as a group, experienced their largest diversification of the entire Mesozoic era in the Yixian. On the other hand, some invertebrate groups, such as bivalves and gastropods (snails and slugs), were numerous but low in diversity, being mainly represented by one or two dominant species ( Arguniella in the case of the bivalves). Studies of vertebrates have shown support for
14952-532: The area passed to the Chinese Communist Party and its leader Mao Zedong , the fossils of Yixian were studied only by Chinese scientists. It was not until the 1990s when remarkable fossils of birds and other non-avian dinosaurs were excavated. Since 1996, a number of dinosaur fossils that have revolutionized knowledge of these animals have been found at Yixian; among them are the first known non- avian theropods with feathers . For some time,
15120-673: The best-known genera are remarkable for their large size, many Mesozoic dinosaurs were human-sized or smaller, and modern birds are generally small in size. Dinosaurs today inhabit every continent, and fossils show that they had achieved global distribution by the Early Jurassic epoch at latest. Modern birds inhabit most available habitats, from terrestrial to marine, and there is evidence that some non-avian dinosaurs (such as Microraptor ) could fly or at least glide, and others, such as spinosaurids , had semiaquatic habits. While recent discoveries have made it more difficult to present
15288-455: The body . Other prehistoric animals, including pterosaurs , mosasaurs , ichthyosaurs , plesiosaurs , and Dimetrodon , while often popularly conceived of as dinosaurs, are not taxonomically classified as dinosaurs. Pterosaurs are distantly related to dinosaurs, being members of the clade Ornithodira . The other groups mentioned are, like dinosaurs and pterosaurs, members of Sauropsida (the reptile and bird clade), except Dimetrodon (which
15456-429: The bone as the lower extremity of the femur of a large animal, and recognized that it was too large to belong to any known species. He therefore concluded it to be the femur of a huge human, perhaps a Titan or another type of giant featured in legends. Edward Lhuyd , a friend of Sir Isaac Newton , published Lithophylacii Britannici ichnographia (1699), the first scientific treatment of what would now be recognized as
15624-549: The breakaway Republic of Ezo . An expeditionary force was dispatched by the new government and the Ezo Republic forces were overwhelmed. The siege of Hakodate came to an end in May 1869 and the remaining forces surrendered. The Charter Oath was made public at the enthronement of Emperor Meiji of Japan on April 7, 1868. The Oath outlined the main aims and the course of action to be followed during Emperor Meiji's reign, setting
15792-461: The cabinet demanded that there be guarantees from the British in return for the risks and costs of the major deployment of Japanese troops. On July 6, 1900, the 5th Infantry Division was alerted for possible deployment to China, but no timetable was set for this. Two days later, with more ground troops urgently needed to lift the siege of the foreign legations at Peking, the British ambassador offered
15960-638: The centuries-old Chinese suzerainty . On June 4, 1894, Korea requested aid from the Qing Empire in suppressing the Donghak Rebellion . The Qing government sent 2,800 troops to Korea. The Japanese countered by sending an 8,000-troop expeditionary force (the Oshima Composite Brigade) to Korea. The first 400 troops arrived on June 9 en route to Seoul , and 3,000 landed at Incheon on June 12. The Qing government turned down Japan's suggestion for Japan and China to cooperate to reform
16128-438: The chonmage ( chonmage ) hairstyle. During the early 20th century, the government was suspicious towards a number of unauthorized religious movements and periodically made attempts to suppress them. Government suppression was especially severe from the 1930s until the early 1940s, when the growth of Japanese nationalism and State Shinto were closely linked. Under the Meiji regime lèse majesté prohibited insults against
16296-699: The command of Captain Shimamura Hayao . The Japanese were able to contribute 52 men to the Seymour Expedition . On 12 June 1900, the advance of the Seymour Expedition was halted some 50 kilometres (30 mi) from the capital, by mixed Boxer and Chinese regular army forces. The vastly outnumbered allies withdrew to the vicinity of Tianjin , having suffered more than 300 casualties. The army general staff in Tokyo had become aware of
16464-475: The common theropods, and ankylosaurids and early ceratopsians like Psittacosaurus became important herbivores. Meanwhile, Australia was home to a fauna of basal ankylosaurians, hypsilophodonts , and iguanodontians. The stegosaurians appear to have gone extinct at some point in the late Early Cretaceous or early Late Cretaceous . A major change in the Early Cretaceous, which would be amplified in
16632-514: The country was forced open to trade by the Convention of Kanagawa which came when Matthew C. Perry arrived in Japan in 1854. Thus, the period known as Bakumatsu began. The following years saw increased foreign trade and interaction; commercial treaties between the Tokugawa shogunate and Western countries were signed. In large part due to the humiliating terms of these unequal treaties ,
16800-573: The countryside, meant that abattoirs and workers were met with hostility from local residents. Continued ostracism as well as the decline in living standards led to former burakumin communities turning into slum areas. In the Blood tax riots , the Japanese Meiji government brutally put down revolts by Japanese samurai angry over the legal revocation of the traditional untouchable status of burakumin. The social tension continued to grow during
16968-602: The decentralized American system with no central bank. In 1871, the New Currency Act of Meiji 4 (1871) abolished the local currencies and established the yen as the new decimal currency. It had parity with the Mexican silver dollar. The First Sino-Japanese War , fought in 1894 and 1895, revolved around the issue of control and influence over Korea under the rule of the Joseon dynasty . Korea had traditionally been
17136-731: The dinosaur subgroup Maniraptora , which are coelurosaurs , which are theropods, which are saurischians. Research by Matthew G. Baron, David B. Norman , and Paul M. Barrett in 2017 suggested a radical revision of dinosaurian systematics. Phylogenetic analysis by Baron et al. recovered the Ornithischia as being closer to the Theropoda than the Sauropodomorpha, as opposed to the traditional union of theropods with sauropodomorphs. This would cause sauropods and kin to fall outside traditional dinosaurs, so they re-defined Dinosauria as
17304-427: The dinosaurs' modern-day surviving avian lineage (birds) are generally small due to the constraints of flight, many prehistoric dinosaurs (non-avian and avian) were large-bodied—the largest sauropod dinosaurs are estimated to have reached lengths of 39.7 meters (130 feet) and heights of 18 m (59 ft) and were the largest land animals of all time. The misconception that non-avian dinosaurs were uniformly gigantic
17472-686: The dinosaurs. Most of these other animals became extinct in the Triassic, in one of two events. First, at about 215 million years ago, a variety of basal archosauromorphs, including the protorosaurs , became extinct. This was followed by the Triassic–Jurassic extinction event (about 201 million years ago), that saw the end of most of the other groups of early archosaurs, like aetosaurs, ornithosuchids, phytosaurs , and rauisuchians. Rhynchosaurs and dicynodonts survived (at least in some areas) at least as late as early –mid Norian and late Norian or earliest Rhaetian stages , respectively, and
17640-474: The division of the Jehol into phases, and the diversity of fish in the Yixian was distinct from older and younger formations, with Lycoptera as the dominant species. The Yixian preserves the first Jehol dinosaurs and pterosaurs (which have not been found in the older Dabeigou Formation), and the first major radiation of birds (only one bird species is known from the Dabeigou). The Yixian also preserves
17808-760: The dominant terrestrial vertebrates after the Triassic–Jurassic extinction event 201.3 mya and their dominance continued throughout the Jurassic and Cretaceous periods. The fossil record shows that birds are feathered dinosaurs , having evolved from earlier theropods during the Late Jurassic epoch , and are the only dinosaur lineage known to have survived the Cretaceous–Paleogene extinction event approximately 66 mya. Dinosaurs can therefore be divided into avian dinosaurs —birds—and
17976-658: The dromaeosaurid Tianyuraptor , the compsognathid Sinosauropteryx and the tyrannosauroid Dilong . Microraptor also hails from this formation, as well as from the younger Jiufotang Formation . However, other microraptorines, such as Sinornithosaurus and Graciliraptor , also inhabit the Yixian. A limnic eruption may have preserved many of the fossils, excluding Dongbeititan . Empire of Japan Unitary parliamentary semi-constitutional monarchy (1889–1947) The Empire of Japan , also known as the Japanese Empire or Imperial Japan ,
18144-585: The early saurischian Alwalkeria , are known from the Upper Maleri and Lower Maleri Formations of India. The Carnian-aged Chañares Formation of Argentina preserves primitive, dinosaur-like ornithodirans such as Lagosuchus and Lagerpeton in Argentina , making it another important site for understanding dinosaur evolution. These ornithodirans support the model of early dinosaurs as small, bipedal predators. Dinosaurs may have appeared as early as
18312-437: The emperor, agreeing to "be the instrument for carrying out" imperial orders, leading to the end of the Tokugawa shogunate. However, while Yoshinobu's resignation had created a nominal void at the highest level of government, his apparatus of state continued to exist. Moreover, the shogunal government, the Tokugawa family in particular, remained a prominent force in the evolving political order and retained many executive powers,
18480-462: The end of the Cretaceous, caused the extinction of all dinosaur groups except for the neornithine birds. Some other diapsid groups, including crocodilians , dyrosaurs , sebecosuchians , turtles, lizards , snakes , sphenodontians , and choristoderans , also survived the event. The surviving lineages of neornithine birds, including the ancestors of modern ratites , ducks and chickens , and
18648-475: The eventual loss of many of Japan's Oceanian island possessions in the following three years. Eventually, the American military captured Iwo Jima and Okinawa Island , leaving the Japanese mainland unprotected and without a significant naval defense force. By August 1945, plans had been made for an Allied invasion of mainland Japan , but were shelved after Japan surrendered in the face of a major breakthrough by
18816-456: The exact date of their extinction is uncertain. These losses left behind a land fauna of crocodylomorphs , dinosaurs, mammals, pterosaurians, and turtles . The first few lines of early dinosaurs diversified through the Carnian and Norian stages of the Triassic, possibly by occupying the niches of the groups that became extinct. Also notably, there was a heightened rate of extinction during
18984-505: The extinct non-avian dinosaurs , which are all dinosaurs other than birds. Dinosaurs are varied from taxonomic , morphological and ecological standpoints. Birds, at over 11,000 living species , are among the most diverse groups of vertebrates. Using fossil evidence, paleontologists have identified over 900 distinct genera and more than 1,000 different species of non-avian dinosaurs. Dinosaurs are represented on every continent by both extant species (birds) and fossil remains. Through
19152-463: The few great powers that determine the fate of the world. In the 1860s, Japan began to experience great social turmoil and rapid modernization. The feudal caste system in Japan formally ended in 1869 with the Meiji restoration . In 1871, the newly formed Meiji government issued a decree called Senmin Haishirei ( 賤民廃止令 Edict Abolishing Ignoble Classes ) giving burakumin equal legal status. It
19320-433: The field of dinosaur research experienced a surge in activity that remains ongoing. Several seminal studies led to this activity. First, John Ostrom discovered the bird-like dromaeosaurid theropod Deinonychus and described it in 1969. Its anatomy indicated that it was an active predator that was likely warm-blooded, in marked contrast to the then-prevailing image of dinosaurs. Concurrently, Robert T. Bakker published
19488-478: The first half of the 20th century, before birds were recognized as dinosaurs, most of the scientific community believed dinosaurs to have been sluggish and cold-blooded . Most research conducted since the 1970s , however, has indicated that dinosaurs were active animals with elevated metabolisms and numerous adaptations for social interaction. Some were herbivorous , others carnivorous . Evidence suggests that all dinosaurs were egg-laying , and that nest -building
19656-516: The formation was believed to be from the Late Jurassic – Early Cretaceous boundary, some 145 mya (million years ago). Radiometric dating has since resolved it to be younger; it is now considered to have been deposited in the Barremian , some 125.8–124.1 mya. The Yixian Formation forms the lowest part of the Jehol group , defined by Gu (1962 and 1983) as a group of geological formations including
19824-486: The hip structure of their ancestors, with a pubis bone directed cranially , or forward. This basic form was modified by rotating the pubis backward to varying degrees in several groups ( Herrerasaurus , therizinosauroids, dromaeosaurids, and birds ). Saurischia includes the theropods (exclusively bipedal and with a wide variety of diets) and sauropodomorphs (long-necked herbivores which include advanced, quadrupedal groups). By contrast, ornithischians—"bird-hipped", from
19992-488: The immediate establishment of an elected national assembly , and the promulgation of a constitution. The constitution recognized the need for change and modernization after the removal of the shogunate : We, the Successor to the prosperous Throne of Our Predecessors, do humbly and solemnly swear to the Imperial Founder of Our House and to Our other Imperial Ancestors that, in pursuance of a great policy co-extensive with
20160-436: The largest (and only) mammal radiation so far known from the Jehol group. Most vertebrates showed a tendency to climb trees or become arboreal , including many tree-dwelling birds, and climbing mammals and lizards. Plant life reached its Jehol biota peak in the Yixian. Five species of flowering plant were present (three of Archaefructus , one of Archaeamphora and one of Hyrcantha (formerly Sinocarpus ), as were
20328-432: The last common ancestor of Triceratops horridus , Passer domesticus and Diplodocus carnegii , and all of its descendants, to ensure that sauropods and kin remain included as dinosaurs. They also resurrected the clade Ornithoscelida to refer to the group containing Ornithischia and Theropoda. Using one of the above definitions, dinosaurs can be generally described as archosaurs with hind limbs held erect beneath
20496-572: The late 17th century in England. Part of a bone, now known to have been the femur of a Megalosaurus , was recovered from a limestone quarry at Cornwell near Chipping Norton , Oxfordshire, in 1676. The fragment was sent to Robert Plot , Professor of Chemistry at the University of Oxford and first curator of the Ashmolean Museum , who published a description in his The Natural History of Oxford-shire (1677). He correctly identified
20664-526: The legal stage for Japan's modernization. The Meiji leaders also aimed to boost morale and win financial support for the new government . Japan dispatched the Iwakura Mission in 1871. The mission traveled the world in order to renegotiate the unequal treaties with the United States and European countries that Japan had been forced into during the Tokugawa shogunate, and to gather information on western social and economic systems, in order to effect
20832-478: The longest were the 33.5-meter (110 ft) long Diplodocus hallorum (formerly Seismosaurus ), the 33-to-34-meter (108 to 112 ft) long Supersaurus , and 37-meter (121 ft) long Patagotitan ; and the tallest, the 18-meter (59 ft) tall Sauroposeidon , which could have reached a sixth-floor window. There were a few dinosaurs that was considered either the heaviest and longest. The most famous one include Amphicoelias fragillimus , known only from
21000-565: The modernization of Japan. Renegotiation of the unequal treaties was universally unsuccessful, but close observation of the American and European systems inspired members on their return to bring about modernization initiatives in Japan. Japan made a territorial delimitation treaty with Russia in 1875, gaining all the Kuril islands in exchange for Sakhalin island . The Japanese government sent observers to Western countries to observe and learn their practices, and also paid " foreign advisors " in
21168-479: The most complete theropod specimens, while North American localities have produced the most complete sauropodomorph specimens. Prior to the dinosaur renaissance, dinosaurs were mostly classified using the traditional rank-based system of Linnaean taxonomy . The renaissance was also accompanied by the increasingly widespread application of cladistics , a more objective method of classification based on ancestry and shared traits, which has proved tremendously useful in
21336-509: The most important advantage was dietary. Large animals are more efficient at digestion than small animals, because food spends more time in their digestive systems. This also permits them to subsist on food with lower nutritive value than smaller animals. Sauropod remains are mostly found in rock formations interpreted as dry or seasonally dry, and the ability to eat large quantities of low-nutrient browse would have been advantageous in such environments. Scientists will probably never be certain of
21504-478: The most recent common ancestor of a certain taxonomic group, are called the synapomorphies of such a group. A detailed assessment of archosaur interrelations by Sterling Nesbitt confirmed or found the following twelve unambiguous synapomorphies, some previously known: Nesbitt found a number of further potential synapomorphies and discounted a number of synapomorphies previously suggested. Some of these are also present in silesaurids , which Nesbitt recovered as
21672-466: The mouth, including potential cheek -like organs to keep food in the mouth, and jaw motions to grind food. Another notable evolutionary event of the Jurassic was the appearance of true birds, descended from maniraptoran coelurosaurians. By the Early Cretaceous and the ongoing breakup of Pangaea, dinosaurs were becoming strongly differentiated by landmass. The earliest part of this time saw
21840-610: The murder of an Englishman, Charles Lennox Richardson , by a party of samurai from Satsuma . The British demanded reparations but were denied. While attempting to exact payment, the Royal Navy was fired on from coastal batteries near the town of Kagoshima . They responded by bombarding the port of Kagoshima in 1863. The Tokugawa government agreed to pay an indemnity for Richardson's death. Shelling of foreign shipping in Shimonoseki and attacks against foreign property led to
22008-768: The now-splitting supercontinent Gondwana , abelisaurids were the common theropods, and titanosaurian sauropods the common herbivores. Finally, in Europe, dromaeosaurids, rhabdodontid iguanodontians, nodosaurid ankylosaurians, and titanosaurian sauropods were prevalent. Flowering plants were greatly radiating, with the first grasses appearing by the end of the Cretaceous. Grinding hadrosaurids and shearing ceratopsians became very diverse across North America and Asia. Theropods were also radiating as herbivores or omnivores , with therizinosaurians and ornithomimosaurians becoming common. The Cretaceous–Paleogene extinction event, which occurred approximately 66 million years ago at
22176-756: The number of named genera began to increase exponentially in the 1990s. As of 2008, over 30 new species of dinosaurs were named each year. At least sauropodomorphs experienced a further increase in the number of named species in the 2010s, with an average of 9.3 new species having been named each year between 2009 and 2020. As a consequence, more sauropodomorphs were named between 1990 and 2020 than in all previous years combined. These new localities also led to improvements in overall specimen quality, with new species being increasingly named not on scrappy fossils but on more complete skeletons, sometimes from multiple individuals. Better specimens also led to new species being invalidated less frequently. Asian localities have produced
22344-438: The pair's rough methods: for example, their diggers often used dynamite to unearth bones. Modern paleontologists would find such methods crude and unacceptable, since blasting easily destroys fossil and stratigraphic evidence. Despite their unrefined methods, the contributions of Cope and Marsh to paleontology were vast: Marsh unearthed 86 new species of dinosaur and Cope discovered 56, a total of 142 new species. Cope's collection
22512-408: The presence of proteins such as collagen, elastin , and laminin . Both specimens yielded collagen protein sequences that were viable for molecular phylogenetic analyses , which grouped them with birds as would be expected. The extraction of fragmentary DNA has also been reported for both of these fossils, along with a specimen of Hypacrosaurus . In 2015, Sergio Bertazzo and colleagues reported
22680-458: The preservation of collagen fibres and red blood cells in eight Cretaceous dinosaur specimens that did not show any signs of exceptional preservation, indicating that soft tissue may be preserved more commonly than previously thought. Suggestions that these structures represent bacterial biofilms have been rejected, but cross-contamination remains a possibility that is difficult to detect. Dinosaurs diverged from their archosaur ancestors during
22848-422: The rebbachisaurid Nigersaurus . There were three general dinosaur faunas in the Late Cretaceous. In the northern continents of North America and Asia, the major theropods were tyrannosaurids and various types of smaller maniraptoran theropods, with a predominantly ornithischian herbivore assemblage of hadrosaurids, ceratopsians, ankylosaurids, and pachycephalosaurians. In the southern continents that had made up
23016-595: The rest of the Axis powers , the formalized Japanese Instrument of Surrender was issued on 2 September 1945 in compliance with the Potsdam Declaration of the Allies , and the empire's territory subsequently shrunk to cover only the Japanese archipelago resembling modern Japan. Under the slogans of fukoku kyōhei and shokusan kōgyō , which followed the Boshin War and the restoration of power to
23184-1362: The rocks that produced the Jehol (Early Cretaceous) and Yanliao (Mid-to-Late Jurassic) biotas of northeastern China, from which hundreds of dinosaur specimens bearing impressions of feather-like structures (both closely related to birds and otherwise, see § Origin of birds ) have been described by Xing Xu and colleagues. In living reptiles and mammals, pigment-storing cellular structures known as melanosomes are partially responsible for producing colouration. Both chemical traces of melanin and characteristically shaped melanosomes have been reported from feathers and scales of Jehol and Yanliao dinosaurs, including both theropods and ornithischians. This has enabled multiple full-body reconstructions of dinosaur colouration , such as for Sinosauropteryx and Psittacosaurus by Jakob Vinther and colleagues, and similar techniques have also been extended to dinosaur fossils from other localities. (However, some researchers have also suggested that fossilized melanosomes represent bacterial remains. ) Stomach contents in some Jehol and Yanliao dinosaurs closely related to birds have also provided indirect indications of diet and digestive system anatomy (e.g., crops ). More concrete evidence of internal anatomy has been reported in Scipionyx from
23352-479: The samurai class, which was abolished together with the caste system. This would later bring the Meiji government into conflict with the samurai . Several writers, under the constant threat of assassination from their political foes, were influential in winning Japanese support for westernization . One such writer was Fukuzawa Yukichi , whose works included "Conditions in the West", " Leaving Asia ", and "An Outline of
23520-450: The sauropodomorphs Bagualosaurus , Buriolestes , Guaibasaurus , Macrocollum , Nhandumirim , Pampadromaeus , Saturnalia , and Unaysaurus . The Pebbly Arkose Formation, which is of uncertain age but was likely comparable to the other two, has produced the sauropodomorph Mbiresaurus , along with an unnamed herrerasaurid. Less well-preserved remains of the sauropodomorphs Jaklapallisaurus and Nambalia , along with
23688-416: The sauropodomorphs Chromogisaurus , Eodromaeus , and Panphagia . Eoraptor 's likely resemblance to the common ancestor of all dinosaurs suggests that the first dinosaurs would have been small, bipedal predators . The Santa Maria Formation (radiometrically dated to be older, at 233.23 million years old ) has produced the herrerasaurids Gnathovorax and Staurikosaurus , along with
23856-505: The shogunate soon faced internal hostility, which materialized into a radical, xenophobic movement, the sonnō jōi (literally "Revere the Emperor, expel the barbarians"). In March 1863, the Emperor issued the " order to expel barbarians ." Although the shogunate had no intention of enforcing the order, it nevertheless inspired attacks against the shogunate itself and against foreigners in Japan. The Namamugi Incident during 1862 led to
24024-584: The skeleton now mounted and on display at the Museum für Naturkunde in Berlin ; this mount is 12 meters (39 ft) tall and 21.8 to 22.5 meters (72 to 74 ft) long, and would have belonged to an animal that weighed between 30 000 and 60 000 kilograms ( 70 000 and 130 000 lb). The longest complete dinosaur is the 27 meters (89 ft) long Diplodocus , which was discovered in Wyoming in
24192-406: The skull behind the eyes), and as members of the diapsid group Archosauria, had additional openings in the snout and lower jaw. Additionally, several characteristics once thought to be synapomorphies are now known to have appeared before dinosaurs, or were absent in the earliest dinosaurs and independently evolved by different dinosaur groups. These include an elongated scapula , or shoulder blade;
24360-573: The slightly younger Jiufotang Formation and the Fuxin Formation . Chiappe et al. argued in 1999 that the oldest beds of the Yixian (those bearing a fauna dominated by confuciusornithid birds ) were best separated as a distinct formation, called the Chaomidianzi Formation , with a type locality at the village of Sihetun, approximately 25 km south of Beipiao City. However, this classification has fallen out of favor, and
24528-434: The sole surviving dinosaurs. In traditional taxonomy , birds were considered a separate class that had evolved from dinosaurs, a distinct superorder . However, most contemporary paleontologists reject the traditional style of classification based on anatomical similarity, in favor of phylogenetic taxonomy based on deduced ancestry, in which each group is defined as all descendants of a given founding genus. Birds belong to
24696-515: The specimen's excavation. Owen and Hooley subsequently described skin impressions of Hypsilophodon and Iguanodon in 1885 and 1917. Since then, scale impressions have been most frequently found among hadrosaurids, where the impressions are known from nearly the entire body across multiple specimens. Starting from the 1990s, major discoveries of exceptionally preserved fossils in deposits known as conservation Lagerstätten contributed to research on dinosaur soft tissues. Chiefly among these were
24864-538: The spread of ankylosaurians, iguanodontians , and brachiosaurids through Europe, North America, and northern Africa . These were later supplemented or replaced in Africa by large spinosaurid and carcharodontosaurid theropods, and rebbachisaurid and titanosaurian sauropods, also found in South America . In Asia , maniraptoran coelurosaurians like dromaeosaurids, troodontids , and oviraptorosaurians became
25032-468: The study of dinosaur systematics and evolution. Cladistic analysis, among other techniques, helps to compensate for an often incomplete and fragmentary fossil record. Reference books summarizing the state of dinosaur research, such as David B. Weishampel and colleagues' The Dinosauria , made knowledge more accessible and spurred further interest in dinosaur research. The release of the first and second editions of The Dinosauria in 1990 and 2004, and of
25200-459: The taxonomic name has often been interpreted as a reference to dinosaurs' teeth, claws, and other fearsome characteristics, Owen intended it also to evoke their size and majesty. Owen recognized that the remains that had been found so far, Iguanodon , Megalosaurus and Hylaeosaurus , shared distinctive features, and so decided to present them as a distinct taxonomic group. As clarified by British geologist and historian Hugh Torrens, Owen had given
25368-623: The time was heavily engaged in the Boer War , so a large part of the British army was tied down in South Africa. Further, deploying large numbers of troops from its garrisons in India would take too much time and weaken internal security there. Overriding personal doubts, Foreign Minister Aoki Shūzō calculated that the advantages of participating in an allied coalition were too attractive to ignore. Prime Minister Yamagata agreed, but others in
25536-849: The total number of dinosaur genera preserved in the fossil record at 1850, nearly 75% still undiscovered, and the number that ever existed (in or out of the fossil record) at 3,400. A 2016 estimate put the number of dinosaur species living in the Mesozoic at 1,543–2,468, compared to the number of modern-day birds (avian dinosaurs) at 10,806 species. Extinct dinosaurs, as well as modern birds, include genera that are herbivorous and others carnivorous, including seed-eaters, fish-eaters, insectivores, and omnivores. While dinosaurs were ancestrally bipedal (as are all modern birds), some evolved into quadrupeds, and others, such as Anchisaurus and Iguanodon , could walk as easily on two or four legs. Cranial modifications like horns and crests are common dinosaurian traits, and some extinct species had bony armor. Although
25704-587: The total, 20,300 were Imperial Japanese Army troops of the 5th Infantry Division under Lt. General Yamaguchi Motoomi; the remainder were 540 naval rikusentai (marines) from the Imperial Japanese Navy . At the beginning of the Boxer Rebellion the Japanese only had 215 troops in northern China stationed at Tientsin; nearly all of them were naval rikusentai from the Kasagi and the Atago , under
25872-475: The two-hundred-year-old Tokugawa shogunate. Tokugawa Yoshinobu launched a military campaign to seize the emperor's court in Kyoto. However, the tide rapidly turned in favor of the smaller but relatively modernized imperial faction and resulted in defections of many daimyōs to the Imperial side. The Battle of Toba–Fushimi was a decisive victory in which a combined army from Chōshū, Tosa, and Satsuma domains defeated
26040-549: The worsening conditions in China and had drafted ambitious contingency plans, but in the wake of the Triple Intervention five years before, the government refused to deploy large numbers of troops unless requested by the western powers. However three days later, a provisional force of 1,300 troops commanded by Major General Fukushima Yasumasa was to be deployed to northern China. Fukushima was chosen because he spoke fluent English which enabled him to communicate with
26208-402: Was a trait shared by many dinosaurs, both avian and non-avian. While dinosaurs were ancestrally bipedal , many extinct groups included quadrupedal species, and some were able to shift between these stances. Elaborate display structures such as horns or crests are common to all dinosaur groups, and some extinct groups developed skeletal modifications such as bony armor and spines . While
26376-456: Was among the first Protestant literature in Japan. In 1865, McCartee moved back to Ningbo , China, but others have followed in his footsteps. There was a burst of growth of Christianity in the late 19th century when Japan re-opened its doors to the West. Protestant church growth slowed dramatically in the early 20th century under the influence of the military government during the Shōwa period . Under
26544-457: Was an extremely important find: Hadrosaurus was one of the first nearly complete dinosaur skeletons found ( the first was in 1834, in Maidstone, England ), and it was clearly a bipedal creature. This was a revolutionary discovery as, until that point, most scientists had believed dinosaurs walked on four feet, like other lizards. Foulke's discoveries sparked a wave of interests in dinosaurs in
26712-437: Was an order of magnitude more massive than anything else that has since walked the Earth. Giant prehistoric mammals such as Paraceratherium (the largest land mammal ever) were dwarfed by the giant sauropods, and only modern whales approach or surpass them in size. There are several proposed advantages for the large size of sauropods, including protection from predation, reduction of energy use, and longevity, but it may be that
26880-424: Was characterized by rapid industrialization , the development of a capitalist economy , and the transformation of many feudal workers to wage labour . The use of strike action also increased, and 1897, with the establishment of a union for metalworkers, the foundations of the modern Japanese trade-union movement were formed. Samurai were allowed to work in any occupation they wanted. Admission to universities
27048-422: Was determined based on examination results. The government also recruited more than 3,000 Westerners to teach modern science, mathematics, technology, and foreign languages in Japan ( O-yatoi gaikokujin ). Despite this, social mobility was still low due to samurai and their descendants being overrepresented in the new elite class. After sending observers to the United States, the Empire of Japan initially copied
27216-758: Was enacted, officially ending the Japanese Empire and forming modern Japan . During this time, the Imperial Japanese Armed Forces were dissolved. It was later replaced by the current Japan Self-Defense Forces in 1954. Reconstruction under the Allied occupation continued until 1952, consolidating the modern Japanese constitutional monarchy . In total, the Empire of Japan had three emperors: Meiji , Taishō , and Shōwa . The Imperial era came to an end partway through Shōwa's reign , and he remained emperor until 1989. The historical state
27384-519: Was founded, de jure , after the 1889 signing of Constitution of the Empire of Japan. The constitution formalized much of the Empire's political structure and gave many responsibilities and powers to the Emperor. In 1890, the Imperial Diet was established in response to the Meiji Constitution. The Diet consisted of the House of Representatives of Japan and the House of Peers . Both houses opened seats for colonial people as well as Japanese. The Imperial Diet continued until 1947. Economic development
27552-417: Was prompted by his learning of a series of arson attacks in Edo, starting with the burning of the outworks of Edo Castle , the main Tokugawa residence. The Boshin War ( 戊辰戦争 , Boshin Sensō ) was fought between January 1868 and May 1869. The alliance of samurai from southern and western domains and court officials had now secured the cooperation of the young Emperor Meiji, who ordered the dissolution of
27720-450: Was purportedly discovered in 1822 by Mary Ann Mantell , the wife of English geologist Gideon Mantell , though this is disputed and some historians say Gideon had acquired remains years earlier. Gideon Mantell recognized similarities between his fossils and the bones of modern iguanas and published his findings in 1825. The study of these "great fossil lizards" soon became of great interest to European and American scientists, and in 1842
27888-415: Was repressed and adherents were persecuted. After the Tokugawa shogunate banned Christianity in 1620, it ceased to exist publicly. Many Catholics went underground, becoming hidden Christians ( 隠れキリシタン , kakure kirishitan ) , while others lost their lives. After Japan was opened to foreign powers in 1853, many Christian clergymen were sent from Catholic, Protestant, and Orthodox churches, though proselytism
28056-426: Was still banned. Only after the Meiji Restoration, was Christianity re-established in Japan. Freedom of religion was introduced in 1871, giving all Christian communities the right to legal existence and preaching. Eastern Orthodoxy was brought to Japan in the 19th century by St. Nicholas (baptized as Ivan Dmitrievich Kasatkin), who was sent in 1861 by the Russian Orthodox Church to Hakodate , Hokkaidō as priest to
28224-457: Was the Japanese nation-state that existed from the Meiji Restoration on 3 January 1868 until the Constitution of Japan took effect on 3 May 1947. From 1910 to 1945 , it included the Japanese archipelago , the Kurils , Karafuto , Korea , and Taiwan . Concessions such as the Kwantung Leased Territory were de jure not parts of the empire but dependent territories. In the closing stages of World War II , with Japan defeated alongside
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