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Tetanurans
Tetanurae (/ˌtɛtəˈnjuːriː/ or "stiff tails") is a clade that includes most theropod dinosaurs, including megalosauroids, allosauroids, tyrannosauroids, ornithomimosaurs, compsognathids and maniraptorans (including birds). Tetanurans are defined as all theropods more closely related to modern birds than to '' Ceratosaurus'' and contain the majority of predatory dinosaur diversity. Tetanurae likely diverged from its sister group, Ceratosauria, during the late Triassic. Tetanurae first appeared in the fossil record by the Early Jurassic about 190 mya and by the Middle Jurassic had become globally distributed. The group was named by Jacques Gauthier in 1986 and originally had two main subgroups: Carnosauria and Coelurosauria, the clade containing birds and related dinosaurs such as compsognathids, tyrannosaurids, ornithomimosaurs, and maniraptorans. The original Carnosauria was a polyphyletic group including any large carnivorous theropod. Many of Gauthier's carnosaurs, su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orionides
Orionides is a clade of tetanuran theropod dinosaurs from the Middle Jurassic to the Present. The clade includes most theropod dinosaurs, including birds. Relationships Although many phylogenetic analyses found basal tetanurans that were outside both Megalosauroidea and Avetheropoda, the core dichotomy was named only in 2012. Carrano, Benson and Sampson (2012) named that clade Orionides, and defined it as the node comprising Megalosauroidea, Avetheropoda, their most recent common ancestor, and all its descendants. In 2015, Hendrickx, Hartman and Mateus clarified this definition, specifying it as the least inclusive clade including ''Allosaurus fragilis'', ''Megalosaurus bucklandii'', and ''Passer domesticus''. The cladogram presented below follows a phylogenetic analysis published by Zanno and Makovicky in 2013. In 2019, a basal Allosauroid by the name of ''Asfaltovenator'' was discovered that provided more evidence to the idea of a monophyletic Carnosauria that contained b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Avetheropoda
Avetheropoda, or "bird theropods", is a clade that includes carnosaurians and coelurosaurs to the exclusion of other dinosaurs. Definition Avetheropoda was named by Gregory S. Paul in 1988, and was first defined as a clade by Currie and Padian in 1997, to include ''Allosaurus'', modern birds, and other animals descended from their most recent ancestor. In 1999, Paul Sereno named another group, Neotetanurae, for the clade containing Allosauroidea and Coelurosauria, and excluding other tetanurans such as megalosauroids, but this definition was published slightly later. A monophyletic Avetheropoda is recovered in many papers, however recent findings suggest a monophyletic Carnosauria model with allosauroids and megalosauroids being each other’s closest relatives instead of Allosaurs and Coelurosaurs. Classification The cladogram A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megalosauroidea
Megalosauroidea (meaning 'great/big lizard forms') is a superfamily (or clade) of tetanuran theropod dinosaurs that lived from the Middle Jurassic to the Late Cretaceous period. The group is defined as '' Megalosaurus bucklandii'' and all taxa sharing a more recent common ancestor with it than with '' Allosaurus fragilis'' or '' Passer domesticus''. Members of the group include '' Spinosaurus'', ''Megalosaurus'', and '' Torvosaurus''. They are possibly paraphyletic in nature. Classification The name Spinosauroidea is sometimes used in place of Megalosauroidea. The superfamily Spinosauroidea was named in 1915 by Ernst Stromer. It is a synonym of Megalosauroidea in almost all modern phylogenetic analyses, and it is therefore redundant. Spinosauroidea was defined as a clade in 1998 by Paul Sereno as the node clade containing the common ancestor of ''Spinosaurus'' and ''Torvosaurus'' and all its descendants. Thomas Holtz in 2004 defined a branch clade with the same name containing a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bird
Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweight skeleton. Birds live worldwide and range in size from the bee hummingbird to the ostrich. There are about ten thousand living species, more than half of which are passerine, or "perching" birds. Birds have whose development varies according to species; the only known groups without wings are the extinct moa and elephant birds. Wings, which are modified forelimbs, gave birds the ability to fly, although further evolution has led to the loss of flight in some birds, including ratites, penguins, and diverse endemic island species. The digestive and respiratory systems of birds are also uniquely adapted for flight. Some bird species of aquatic environments, particularly seabirds and some waterbirds, have further evolved for swim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maniraptora
Maniraptora is a clade of coelurosaurian dinosaurs which includes the birds and the non-avian dinosaurs that were more closely related to them than to ''Ornithomimus velox''. It contains the major subgroups Avialae, Deinonychosauria, Oviraptorosauria and Therizinosauria. '' Ornitholestes'' and the Alvarezsauroidea are also often included. Together with the next closest sister group, the Ornithomimosauria, Maniraptora comprises the more inclusive clade Maniraptoriformes. Maniraptorans first appear in the fossil record during the Jurassic Period (see '' Eshanosaurus''), and survive today as living birds. Description Maniraptorans are characterized by long arms and three-fingered hands (though reduced or fused in some lineages), as well as a "half-moon shaped" (semi-lunate) bone in the wrist (carpus). In 2004, Tom Holtz and Halszka Osmólska pointed out six other maniraptoran characters relating to specific details of the skeleton. Unlike most other saurischian dinosaurs, which h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compsognathidae
Compsognathidae is a family of coelurosaurian theropod dinosaurs. Compsognathids were small carnivores, generally conservative in form, hailing from the Jurassic and Cretaceous Periods. The bird-like features of these species, along with other dinosaurs such as ''Archaeopteryx'' inspired the idea for the connection between dinosaur reptiles and modern-day avian species. Compsognathid fossils preserve diverse integument — skin impressions are known from four genera commonly placed in the group, '' Compsognathus'', '' Sinosauropteryx'', ''Sinocalliopteryx'', and '' Juravenator''.Xu, Xing. "Palaeontology: Scales, feathers and dinosaurs." ''Nature'' 440.7082 (2006): 287-288. While the latter three show evidence of a covering of some of the earliest primitive feathers over much of the body, ''Juravenator'' and ''Compsognathus'' also show evidence of scales on the tail or hind legs. '' Ubirajara'', described in 2020, had elaborate integumentary structures on its back and shoulders sup ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ornithomimosauria
Ornithomimosauria ("bird-mimic lizards") are theropod dinosaurs which bore a superficial resemblance to the modern-day ostrich. They were fast, omnivorous or herbivorous dinosaurs from the Cretaceous Period of Laurasia (now Asia, Europe and North America), as well as Africa and possibly Australia. The group first appeared in the Early Cretaceous and persisted until the Late Cretaceous. Primitive members of the group include '' Nqwebasaurus'', ''Pelecanimimus'', ''Shenzhousaurus'', '' Hexing'' and '' Deinocheirus'', the arms of which reached 2.4 m (8 feet) in length. More advanced species, members of the family Ornithomimidae, include '' Gallimimus'', ''Struthiomimus'', and '' Ornithomimus''. Some paleontologists, like Paul Sereno, consider the enigmatic alvarezsaurids to be close relatives of the ornithomimosaurs and place them together in the superfamily Ornithomimoidea (see classification below). Description The skulls of ornithomimosaurs were small, with large eye ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tyrannosauroidea
Tyrannosauroidea (meaning 'tyrant lizard forms') is a superfamily (or clade) of coelurosaurian theropod dinosaurs that includes the family Tyrannosauridae as well as more basal relatives. Tyrannosauroids lived on the Laurasian supercontinent beginning in the Jurassic Period. By the end of the Cretaceous Period, tyrannosauroids were the dominant large predators in the Northern Hemisphere, culminating in the gigantic ''Tyrannosaurus''. Fossils of tyrannosauroids have been recovered on what are now the continents of North America, Europe and Asia, with fragmentary remains possibly attributable to tyrannosaurs also known from South America and Australia. Tyrannosauroids were bipedal carnivores, as were most theropods, and were characterized by numerous skeletal features, especially of the skull and pelvis. Early in their existence, tyrannosauroids were small predators with long, three-fingered forelimbs. Late Cretaceous genera became much larger, including some of the large ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allosauroidea
Allosauroidea is a superfamily or clade of theropod dinosaurs which contains four families — the Metriacanthosauridae, Allosauridae, Carcharodontosauridae, and Neovenatoridae. Allosauroids, alongside the family Megalosauroidea, were among the apex predators that were active during the Middle Jurassic to Late Cretaceous periods. The most famous and best understood allosauroid is the North American genus ''Allosaurus''. The oldest-known allosauroid, '' Shidaisaurus jinae'', appeared in the early Middle Jurassic about 174 million years ago (Earliest Aalenian stage) of China. The last known definitive surviving members of the group died out around 89 million years ago in Asia ('' Shaochilong'') and South America ('' Mapusaurus''), though the megaraptorans, which survived until the end of Maastrichtian, may belong to the group as well. A frontal assigned to an allosauroid found to be most closely related to '' Sinraptor'' has also been found in the Coniacian (89-86.3 Ma) of A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 the subject of active research. They became the dominant terrestrial vertebrates after the Triassic–Jurassic extinction event 201.3 mya; 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 the extinct non-avian dinosaurs, which are all dinosaurs other than birds. Dinosaurs are varied from taxonomic, morphological and ecological standpoints. Birds, at over 10,700 living species, ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theropoda
Theropoda (; ), whose members are known as theropods, is a dinosaur clade that is characterized by hollow bones and three toes and claws on each limb. Theropods are generally classed as a group of saurischian dinosaurs. They were ancestrally carnivorous, although a number of theropod groups evolved to become herbivores and omnivores. Theropods first appeared during the Carnian age of the late Triassic period 231.4 million years ago ( Ma) and included all the large terrestrial carnivores from the Early Jurassic until at least the close of the Cretaceous, about 66 Ma. In the Jurassic, birds evolved from small specialized coelurosaurian theropods, and are today represented by about 10,500 living species. Biology Diet and teeth Theropods exhibit a wide range of diets, from insectivores to herbivores and carnivores. Strict carnivory has always been considered the ancestral diet for theropods as a group, and a wider variety of diets was historically considered ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coelurosauria
Coelurosauria (; from Greek, meaning "hollow tailed lizards") is the clade containing all theropod dinosaurs more closely related to birds than to carnosaurs. Coelurosauria is a subgroup of theropod dinosaurs that includes compsognathids, tyrannosaurs, ornithomimosaurs, and maniraptorans; Maniraptora includes birds, the only known dinosaur group alive today. Most feathered dinosaurs discovered so far have been coelurosaurs. Philip J. Currie had considered it likely and probable that all coelurosaurs were feathered. However, several skin impressions found for some members of this group show pebbly, scaly skin, indicating that feathers did not completely replace scales in all taxa. In the past, Coelurosauria was used to refer to all small theropods, but this classification has since been abolished. Anatomy Bodyplan The studying of anatomical traits in coelurosaurs indicates that the last common ancestor had evolved the ability to eat and digest plant matter, adapting to an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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