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Yixianosaurus
''Yixianosaurus'' (meaning "Yixian lizard") is a maniraptoran theropod dinosaur genus from the Early Cretaceous of China. The type species, ''Yixianosaurus longimanus'', was formally named and described by Xu Xing and Wang Xiaolin in 2003. Its partial skeleton was discovered in 2001, in Liaoning at Wangjiagou in northeastern China. The generic name refers to the Yixian Formation. The specific name means "with a long hand" from Latin ''longus'', "long", and ''manus'', "hand".Xu, X. and Wang, X. (2003).A new maniraptoran dinosaur from the Early Cretaceous Yixian Formation of western Liaoning. ''Vertebrata PalAsiatica'', 41(3): 195–202. Description ''Yixianosaurus'' is known only from a single specimen, holotype IVPP V12638, which likely derived from the Dawangzhangzi Bed (early Aptian stage, 122 million years ago).Xu, X. and Norell, M.A. (2006). "Non-Avian dinosaur fossils from the Lower Cretaceous Jehol Group of western Liaoning, China."''Geological Journal'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yixianosaurus Longimanus Size Comparison
''Yixianosaurus'' (meaning "Yixian lizard") is a maniraptoran theropod dinosaur genus from the Early Cretaceous of China. The type species, ''Yixianosaurus longimanus'', was formally named and described by Xu Xing and Wang Xiaolin in 2003. Its partial skeleton was discovered in 2001, in Liaoning at Wangjiagou in northeastern China. The generic name refers to the Yixian Formation. The specific name means "with a long hand" from Latin ''longus'', "long", and ''manus'', "hand".Xu, X. and Wang, X. (2003).A new maniraptoran dinosaur from the Early Cretaceous Yixian Formation of western Liaoning. ''Vertebrata PalAsiatica'', 41(3): 195–202. Description ''Yixianosaurus'' is known only from a single specimen, holotype IVPP V12638, which likely derived from the Dawangzhangzi Bed (early Aptian stage, 122 million years ago).Xu, X. and Norell, M.A. (2006). "Non-Avian dinosaur fossils from the Lower Cretaceous Jehol Group of western Liaoning, China."''Geological Journal'', 41 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yixianosaurus Longimanus
''Yixianosaurus'' (meaning "Yixian lizard") is a maniraptoran theropod dinosaur genus from the Early Cretaceous of China. The type species, ''Yixianosaurus longimanus'', was formally named and described by Xu Xing and Wang Xiaolin in 2003. Its partial skeleton was discovered in 2001, in Liaoning at Wangjiagou in northeastern China. The generic name refers to the Yixian Formation. The specific name means "with a long hand" from Latin ''longus'', "long", and ''manus'', "hand".Xu, X. and Wang, X. (2003).A new maniraptoran dinosaur from the Early Cretaceous Yixian Formation of western Liaoning. ''Vertebrata PalAsiatica'', 41(3): 195–202. Description ''Yixianosaurus'' is known only from a single specimen, holotype IVPP V12638, which likely derived from the Dawangzhangzi Bed (early Aptian stage, 122 million years ago).Xu, X. and Norell, M.A. (2006). "Non-Avian dinosaur fossils from the Lower Cretaceous Jehol Group of western Liaoning, China."''Geological Journal'', 41 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xu Xing (paleontologist)
Xu Xing (; born July 1969) is a Chinese paleontologist who has named more dinosaurs than any other living paleontologist. Such dinosaurs include the Jurassic ceratopsian ''Yinlong'', the Jurassic tyrannosauroid ''Guanlong'', the large oviraptorosaur ''Gigantoraptor'', and the troodontid '' Mei''. Biography Xing was born in Xinjiang, China, in 1969. A graduate from the department of geology of Peking University, he is currently a researcher at the Institute of Vertebrate Paleontology and Paleoanthropology of the Chinese Academy of Sciences in Beijing. He had originally planned to become an economist. However, he was assigned to the department of geology by the Chinese authorities. He graduated in 1995, and claims inspiration from Roy Chapman Andrews. Among Xu's paleontological contributions have been discovery and analysis of dinosaur fossils with avian characteristics, and development of theories in regarding the evolution of feather Feathers are epidermal growths that for ... [...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] |
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] |
Scansoriopteryx
''Scansoriopteryx'' ("climbing wing") is a genus of maniraptoran dinosaur. Described from only a single juvenile fossil specimen found in Liaoning, China, ''Scansoriopteryx'' is a sparrow-sized animal that shows adaptations in the foot indicating an arboreal (tree-dwelling) lifestyle. It possessed an unusual, elongated third finger which may have supported a membranous wing, much like the related '' Yi qi''. The type specimen of ''Scansoriopteryx'' also contains the fossilized impression of feathers.Czerkas, S.A., and Yuan, C. (2002). "An arboreal maniraptoran from northeast China." Pp. 63-95 in Czerkas, S.J. (Ed.), ''Feathered Dinosaurs and the Origin of Flight.'' The Dinosaur Museum Journal 1. The Dinosaur Museum, Blanding, U.S.APDF abridged version/ref> Most researchers regard this genus as a synonym of ''Epidendrosaurus'', with some preferring to treat ''Scansoriopteryx'' as the junior synonym,Padian, Kevin. (2001) "Basal Avialae" in "The Dinosauria" in "The Dinosauria: Secon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epidendrosaurus
''Scansoriopteryx'' ("climbing wing") is a genus of maniraptoran dinosaur. Described from only a single juvenile fossil specimen found in Liaoning, China, ''Scansoriopteryx'' is a sparrow-sized animal that shows adaptations in the foot indicating an arboreal (tree-dwelling) lifestyle. It possessed an unusual, elongated third finger which may have supported a membranous wing, much like the related '' Yi qi''. The type specimen of ''Scansoriopteryx'' also contains the fossilized impression of feathers.Czerkas, S.A., and Yuan, C. (2002). "An arboreal maniraptoran from northeast China." Pp. 63-95 in Czerkas, S.J. (Ed.), ''Feathered Dinosaurs and the Origin of Flight.'' The Dinosaur Museum Journal 1. The Dinosaur Museum, Blanding, U.S.APDF abridged version/ref> Most researchers regard this genus as a synonym of ''Epidendrosaurus'', with some preferring to treat ''Scansoriopteryx'' as the junior synonym,Padian, Kevin. (2001) "Basal Avialae" in "The Dinosauria" in "The Dinosauria: Secon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Feathered Dinosaur
A feathered dinosaur is any species of dinosaur possessing feathers. While this includes all species of birds, there is a hypothesis that many, if not all non-avian dinosaur species also possessed feathers in some shape or form. It has been suggested that feathers had originally functioned as thermal insulation, as it remains their function in the down feathers of infant birds today, prior to their eventual modification in birds into structures that support flight. Since scientific research began on dinosaurs in the early 1800s, they were generally believed to be closely related to modern reptiles, such as lizards. The word ''dinosaur'' itself, coined in 1842 by paleontologist Richard Owen, comes from the Greek for 'terrible lizard'. This view began to shift during the so-called dinosaur renaissance in scientific research in the late 1960s, and by the mid-1990s significant evidence had emerged that dinosaurs were much more closely related to birds, which descended directly from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Incertae Sedis
' () or ''problematica'' is a term used for a taxonomic group where its broader relationships are unknown or undefined. Alternatively, such groups are frequently referred to as "enigmatic taxa". In the system of open nomenclature, uncertainty at specific taxonomic levels is indicated by ' (of uncertain family), ' (of uncertain suborder), ' (of uncertain order) and similar terms. Examples *The fossil plant '' Paradinandra suecica'' could not be assigned to any family, but was placed ''incertae sedis'' within the order Ericales when described in 2001. * The fossil ''Gluteus minimus'', described in 1975, could not be assigned to any known animal phylum. The genus is therefore ''incertae sedis'' within the kingdom Animalia. * While it was unclear to which order the New World vultures (family Cathartidae) should be assigned, they were placed in Aves ''incertae sedis''. It was later agreed to place them in a separate order, Cathartiformes. * Bocage's longbill, ''Motacilla bocagii' ... [...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 swimming. B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Humerus
The humerus (; ) is a long bone in the arm that runs from the shoulder to the elbow. It connects the scapula and the two bones of the lower arm, the radius and ulna, and consists of three sections. The humeral upper extremity consists of a rounded head, a narrow neck, and two short processes (tubercles, sometimes called tuberosities). The body is cylindrical in its upper portion, and more prismatic below. The lower extremity consists of 2 epicondyles, 2 processes (trochlea & capitulum), and 3 fossae (radial fossa, coronoid fossa, and olecranon fossa). As well as its true anatomical neck, the constriction below the greater and lesser tubercles of the humerus is referred to as its surgical neck due to its tendency to fracture, thus often becoming the focus of surgeons. Etymology The word "humerus" is derived from la, humerus, umerus meaning upper arm, shoulder, and is linguistically related to Gothic ''ams'' shoulder and Greek ''ōmos''. Structure Upper extremity The upper or pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gastralia
Gastralia (singular gastralium) are dermal bones found in the ventral body wall of modern crocodilians and tuatara, and many prehistoric tetrapods. They are found between the sternum and pelvis, and do not articulate with the vertebrae. In these reptiles, gastralia provide support for the abdomen and attachment sites for abdominal muscles. The possession of gastralia may be ancestral for Tetrapoda and were possibly derived from the ventral scales found in animals like rhipidistians, labyrinthodonts, and ''Acanthostega'', and may be related to ventral elements of turtle plastrons. Similar, but not homologous cartilagenous elements, are found in the ventral body walls of lizards and anurans. These structures have been referred to as inscriptional ribs, based on their alleged association with the inscriptiones tendinae (the tendons that form the six pack in humans). However, the terminology for these gastral-like structures remains confused. Both types, along with sternal ribs ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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