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Phytodinosauria
Phytodinosauria is a group of dinosaurs proposed in 1986, combining the Sauropodomorpha and Ornithischia as sister groups, conceptualized as a superorder of herbivorous dinosaurs excluding the carnivorous Theropoda. This hypothesis has been refuted by modern cladistic analysis, showing such a group to be polyphyletic. Modern studies either combine the Theropoda and Sauropodormorpha in the Saurischia or the Theropoda and Ornithischia in the Ornithoscelida. History In 1888, Harry Govier Seeley divided the Dinosauria into two groups, the Saurischia and the Ornithischia, based on the structure of their pelvis. Since then, it became common to keep these groups separate, even to the extent of considering the Dinosauria to be polyphyletic, not forming a natural group but being just an informal name for unrelated large Archosauria. In 1974 however, Robert T. Bakker, Robert "Bob" Bakker and Peter Malcolm Galton successfully defended the monophyly of the Dinosauria, arguing that the Sauri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saurischia
Saurischia ( , meaning "reptile-hipped" from the Greek ' () meaning 'lizard' and ' () meaning 'hip joint') is one of the two basic divisions of dinosaurs (the other being Ornithischia), classified by their hip structure. Saurischia and Ornithischia were originally called orders by Harry Seeley in 1888, though today most paleontologists classify Saurischia as an unranked clade rather than an order.Weishampel, D.B., Dodson, P., and Osmólska, H. (eds.). (2004). ''The Dinosauria. 2nd edition''. University of California Press, Berkeley. 833 pp. Description All carnivorous dinosaurs (certain types of theropods) are traditionally classified as saurischians, as are all of the birds and one of the two primary lineages of herbivorous dinosaurs, the sauropodomorphs. At the end of the Cretaceous Period, all saurischians except birds became extinct in the course of the Cretaceous–Paleogene extinction event. Birds, as a group of maniraptoran theropod dinosaurs, are a sub-clade of s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sauropodomorpha
Sauropodomorpha ( ; from Greek, meaning "lizard-footed forms") is an extinct clade of long-necked, herbivorous, saurischian dinosaurs that includes the sauropods and their ancestral relatives. Sauropods generally grew to very large sizes, had long necks and tails, were quadrupedal, and became the largest animals to ever walk the Earth. The primitive sauropodomorphs which preceded the sauropods, and are informally called prosauropods, were smaller and were often able to walk on two legs. The sauropodomorphs were the dominant terrestrial herbivores throughout much of the Mesozoic Era, from their origins in the Late Triassic (approximately 230 Ma) until their decline and extinction at the end of the Cretaceous. History of study Early study Gigantic bones of sauropods have been known for thousands of years and become part of legends and cultures but the beginning of their scientific study was in the 1830s. Most of the early taxonomy was based on incomplete and disarticulated mater ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ornithischia
Ornithischia () is an extinct clade of mainly herbivorous dinosaurs characterized by a pelvic structure superficially similar to that of birds. The name ''Ornithischia'', or "bird-hipped", reflects this similarity and is derived from the Greek stem ' (), meaning "bird", and ' (), meaning "hip". However, as theropod dinosaurs, birds are only distantly related to this group. Ornithischians with well known anatomical adaptations include the ceratopsians or "horn-faced" dinosaurs (e.g. ''Triceratops''), the pachycephalosaurs or "thick-headed" dinosaurs, the armored dinosaurs ( Thyreophora) such as stegosaurs and ankylosaurs, and the ornithopods. There is strong evidence that certain groups of ornithischians lived in herds, often segregated by age group, with juveniles forming their own flocks separate from adults. Some were at least partially covered in filamentous (hair- or feather- like) pelts, and there is much debate over whether these filaments found in specimens of '' Ti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ornithoscelida
Ornithoscelida () is a proposed clade that includes various major groupings of dinosaurs. An order Ornithoscelida was originally proposed by Thomas Henry Huxley but later abandoned in favor of Harry Govier Seeley's division of Dinosauria into Saurischia and Ornithischia. The term was revived in 2017 after a new cladistic analysis by Baron ''et al''. Huxley's concept Thomas Henry Huxley originally defined the term in an 1869 lecture as a group comprising two subgroups: the large and heavy-set Dinosauria and the newly discovered ''Compsognathus'', which he placed in a new grouping Compsognatha. The former were defined by their shorter cervical vertebrae, and the femur length exceeding tibia length, and the latter with longer cervical vertebrae, and the femur length shorter than tibia length. He noted that the characteristics of their bones showed many features akin to birds. The dinosaurs Huxley had divided into three families: * Megalosauridae: '' Teratosaurus'', '' Palae ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Therizinosaur
Therizinosaurs (; once called segnosaurs) are an extinct group of large herbivorous theropod dinosaurs whose fossils have been mainly discovered from Cretaceous deposits in Asia and North America. Potential fragmentary remains have also been found in Jurassic deposits of Asia and Europe. Various features of the forelimbs, skull and pelvis unite these finds as both theropods and maniraptorans, making them relatives of birds. The name of the representative genus, '' Therizinosaurus'', is derived from the Greek (, 'to reap' or 'scythe')Translated paper and (, 'lizard'). The older representative, ''Segnosaurus'', is derived from the ('slow') and the Greek . History of research [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Therizinosauria
Therizinosaurs (; once called segnosaurs) are an extinct group of large herbivorous Theropoda, theropod dinosaurs whose fossils have been mainly discovered from Cretaceous deposits in Asia and North America. Potential fragmentary remains have also been found in Jurassic deposits of Asia and Europe. Various features of the forelimbs, skull and pelvis unite these finds as both theropods and maniraptorans, making them relatives of birds. The name of the representative genus, ''Therizinosaurus'', is derived from the Ancient Greek , Greek (, 'to reap' or 'scythe')Translated paper and (, 'lizard'). The older representative, ''Segnosaurus'', is derived from the Latin ('slow') and the Greek . History of research [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anchisaurus
''Anchisaurus'' is a genus of basal sauropodomorph dinosaur. It lived during the Early Jurassic Period, and its fossils have been found in the red sandstone of the Upper Portland Formation, Northeastern United States, which was deposited from the Hettangian age into the Sinemurian age, between about 200 and 192 million years ago.Olsen, P.E. (2002)STRATIGRAPHY AND AGE OF THE EARLY JURASSIC PORTLAND FORMATION OF CONNECTICUT AND MASSACHUSETTS: A CONTRIBUTION TO THE TIME SCALE OF THE EARLY JURASSIC. Session No. 26 Studies of Depositional Systems and Sedimentary Rocks: In Honor of Edward Scudder Belt. 37th Annual Meeting (March 25–27, 2002). Until recently it was classed as a member of Prosauropoda. The genus name ''Anchisaurus'' comes from the Greek ''αγχι'' (') ; "near, close" + Greek ('); "lizard". ''Anchisaurus'' was coined as a replacement name for "''Amphisaurus''", which was itself a replacement name for Hitchcock's "''Megadactylus''", both of which had already bee ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theropod
Theropoda (; from ancient Greek , (''therion'') "wild beast"; , (''pous, podos'') "foot"">wiktionary:ποδός"> (''pous, podos'') "foot" is one of the three major groups (clades) of dinosaurs, alongside Ornithischia and Sauropodomorpha. Theropods, both extant and extinct, are characterized by hollow bones and three toes and claws on each limb. They are generally classed as a group of saurischian dinosaurs, placing them closer to sauropodomorphs than to ornithischians. They were ancestrally carnivorous, although a number of theropod groups evolved to become herbivores and omnivores. Members of the subgroup Coelurosauria and possibly some other or all theropods were covered in feathers. In the Jurassic, birds evolved from small specialized coelurosaurian theropods, and are currently represented by about 11,000 living species, making theropods the only group of dinosaurs alive today. Theropods first appeared during the Carnian age of the late Triassic period ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Convergent Evolution
Convergent evolution is the independent evolution of similar features in species of different periods or epochs in time. Convergent evolution creates analogous structures that have similar form or function but were not present in the last common ancestor of those groups. The cladistic term for the same phenomenon is Cladogram#Homoplasies, homoplasy. The recurrent evolution of flight is a classic example, as flying pterygota, insects, birds, pterosaurs, and bats have independently evolved the useful capacity of flight. Functionally similar features that have arisen through convergent evolution are ''analogous'', whereas ''homology (biology), homologous'' structures or traits have a common origin but can have dissimilar functions. Bird, bat, and pterosaur wings are analogous structures, but their forelimbs are homologous, sharing an ancestral state despite serving different functions. The opposite of convergence is divergent evolution, where related species evolve different trai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brontosaurus Excelsus
''Brontosaurus'' (; meaning "thunder lizard" from the Greek words , "thunder" and , "lizard") is a genus of herbivorous sauropod dinosaur that lived in present-day United States during the Late Jurassic period. It was described by American paleontologist Othniel Charles Marsh in 1879, the type species being dubbed ''B. excelsus'', based on a partial skeleton lacking a skull found in Como Bluff, Wyoming. In subsequent years, two more species of ''Brontosaurus'' were named: ''B. parvus'' in 1902 and ''B. yahnahpin'' in 1994. ''Brontosaurus'' lived about 156 to 146 million years ago (mya) during the Kimmeridgian and Tithonian ages in the Morrison Formation of what is now Utah and Wyoming. For decades, the animal was thought to have been a taxonomic synonym of its close relative ''Apatosaurus'', but a 2015 study by Emmanuel Tschopp and colleagues found it to be distinct. It has seen widespread representation in popular culture, being the archetypal "long-necked" dinosaur in genera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gregory S
Gregory may refer to: People and fictional characters * Gregory (given name), including a list of people and fictional characters with the given name * Gregory (surname), a surname * Gregory (The Walking Dead), fictional character from the walking dead * Gregory (Five Nights at Freddy's), main protagonist of '' Five Nights at Freddy's: Security Breach'' ** Places Australia *Gregory, a town in the Northern Territory * Gregory, Queensland, a town in the Shire of Burke ** Electoral district of Gregory, Queensland, Australia * Gregory, Western Australia. United States * Gregory, South Dakota * Gregory, Tennessee * Gregory, Texas Outer space * Gregory (lunar crater) * Gregory (Venusian crater) Other uses * "Gregory" (''The Americans''), the third episode of the first season of the television series ''The Americans'' See also * Greg (other) * Greggory * Gregoire (other) * Gregor (other) * Gregores (other) * Gregorian (other) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
