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Metriacanthosaurinae
Metriacanthosauridae is an extinct family of allosauroid theropod dinosaurs that lived from the Middle Jurassic to the Early Cretaceous. When broken down into its Greek roots, it means "moderately-spined lizards". The family is split into two subgroups: Metriacanthosaurinae, which includes dinosaurs closely related to '' Metriacanthosaurus'', and another group composed of the close relatives of '' Yangchuanosaurus''. Metriacanthosaurids are considered carnosaurs, belonging to the Allosauroidea superfamily. The group includes species of large range in body size. Of their physical traits, most notable are their neural spines.Bailey, Jack Bowman. "Neural Spine Elongation in Dinosaurs: Sailbacks or Buffalo-Backs?" Journal of Paleontology, vol. 71, no. 06, 1997, pp. 1124–1146., doi:10.1017/s0022336000036076. The records of the group are mostly confined to Asia, though ''Metriacanthosaurus'' is known from Europe. Metriacanthosauridae is used as a senior synonym of Sinraptoridae. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metriacanthosaurus
''Metriacanthosaurus'' (meaning "moderately-spined lizard") is a genus of metriacanthosaurid dinosaur from the upper Oxford Clay of England, dating to the Late Jurassic period, about 160 million years ago (lower Oxfordian). History of discovery In 1923, German paleontologist Friedrich von Huene wrote a paper on Jurassic and Cretaceous European carnivorous dinosaurs within Saurischia. In this paper, he examined a specimen (OUM J.12144) including an incomplete hip, a leg bone, and part of a backbone, assigning it to a new species of ''Megalosaurus'': ''Megalosaurus parkeri''. The specific name honours W. Parker who in the nineteenth century had collected the fossils near Jordan's Cliff at Weymouth. These bones were from the Oxford Clay Formation, which dates to the Upper Jurassic. In 1932, however, von Huene concluded it was a species of '' Altispinax'', ''A. parkeri''. In 1964, scientist Alick Walker decided these fossils were too different from ''Altispinax'', as they lacke ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metriacanthosaurus Parkeri
''Metriacanthosaurus'' (meaning "moderately-spined lizard") is a genus of metriacanthosaurid dinosaur from the upper Oxford Clay of England, dating to the Late Jurassic period, about 160 million years ago (lower Oxfordian). History of discovery In 1923, German paleontologist Friedrich von Huene wrote a paper on Jurassic and Cretaceous European carnivorous dinosaurs within Saurischia. In this paper, he examined a specimen (OUM J.12144) including an incomplete hip, a leg bone, and part of a backbone, assigning it to a new species of ''Megalosaurus'': ''Megalosaurus parkeri''. The specific name honours W. Parker who in the nineteenth century had collected the fossils near Jordan's Cliff at Weymouth. These bones were from the Oxford Clay Formation, which dates to the Upper Jurassic. In 1932, however, von Huene concluded it was a species of '' Altispinax'', ''A. parkeri''. In 1964, scientist Alick Walker decided these fossils were too different from ''Altispinax'', as they lacke ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yangchuanosaurus NT Small
''Yangchuanosaurus'' is an extinct genus of metriacanthosaurid theropod dinosaur that lived in People's Republic of China, China from the Middle Jurassic, Middle to Late Jurassic periods (Bathonian to Oxfordian (stage), Oxfordian stages), and was similar in size and appearance to its North American and European relative, ''Allosaurus''. ''Yangchuanosaurus'' hails from the Upper Shaximiao Formation and was the largest predator in a landscape that included the sauropods ''Mamenchisaurus'' and ''Omeisaurus'' and the Stegosauria, stegosaurs ''Chialingosaurus'', ''Tuojiangosaurus'' and ''Chungkingosaurus''. This theropod was named after the area in which was discovered, Yongchuan, in China. Discovery and species Dong ''et al.'' (1978) named ''Yangchuanosaurus shangyouensis'' on the basis of Municipal Museum of Chongqing, CV 00215, a complete skull and skeleton which was collected from the Shangshaximiao Formation, near Yongchuan, Yongchuan District, Sichuan. It dates to the Oxfo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Siamotyrannus
''Siamotyrannus'' (meaning "Siamese tyrant") is a genus of theropod dinosaur from the early Cretaceous of Thailand. Discovery and naming In 1993, Somchai Traimwichanon found a partial skeleton of a large theropod at the Phu Wiang 9 site in Khon Kaen. In 1996, Eric Buffetaut, Varavudh Suteethorn and Haiyan Tong named and described the type species ''Siamotyrannus isanensis''. The generic name is derived from the old Thai kingdom of Siam, and a Latinised Greek ''tyrannus'', meaning "tyrant", in reference to a presumed membership of the Tyrannosauridae. The specific name is derived from Thai ''isan'', "northeastern part", referring to the provenance from northeast Thailand. The holotype, PW9-1, was found in the Sao Khua Formation, dating from the Berriasian-Barremian. It includes the left half of the pelvis, five rear dorsal vertebrae, the sacrum with five sacrals, and thirteen front tail vertebrae. In 1998, a tibia and some individual teeth were referred to the species. Descrip ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yangchuanosaurus
''Yangchuanosaurus'' is an extinct genus of metriacanthosaurid theropod dinosaur that lived in China from the Middle to Late Jurassic periods (Bathonian to Oxfordian stages), and was similar in size and appearance to its North American and European relative, ''Allosaurus''. ''Yangchuanosaurus'' hails from the Upper Shaximiao Formation and was the largest predator in a landscape that included the sauropods ''Mamenchisaurus'' and ''Omeisaurus'' and the stegosaurs ''Chialingosaurus'', ''Tuojiangosaurus'' and ''Chungkingosaurus''. This theropod was named after the area in which was discovered, Yongchuan, in China. Discovery and species Dong ''et al.'' (1978) named ''Yangchuanosaurus shangyouensis'' on the basis of CV 00215, a complete skull and skeleton which was collected from the Shangshaximiao Formation, near Yongchuan, Yongchuan District, Sichuan. It dates to the Oxfordian stage of the Late Jurassic period, about 161.2 to 157.3 million years ago. It was discovered ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Middle Jurassic
The Middle Jurassic is the second epoch of the Jurassic Period. It lasted from about 174.1 to 163.5 million years ago. Fossils of land-dwelling animals, such as dinosaurs, from the Middle Jurassic are relatively rare, but geological formations containing land animal fossils include the Forest Marble Formation in England, the Kilmaluag Formation in Scotland,British Geological Survey. 2011Stratigraphic framework for the Middle Jurassic strata of Great Britain and the adjoining continental shelf: research report RR/11/06 British Geological Survey, Keyworth, Nottingham. the Daohugou Beds in China, the Itat Formation in Russia, and the Isalo III Formation of western Madagascar. Paleogeography During the Middle Jurassic Epoch, Pangaea began to separate into Laurasia and Gondwana, and the Atlantic Ocean formed. Eastern Laurasia was tectonically active as the Cimmerian plate continued to collide with Laurasia's southern coast, completely closing the Paleo-Tethys Ocean. A subduction zone ... [...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, are among ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carnosauria
Carnosauria is an extinct large group of predatory dinosaurs that lived during the Jurassic and Cretaceous periods. Starting from the 1990s, scientists have discovered some very large carnosaurs in the carcharodontosaurid family, such as ''Giganotosaurus'', ''Mapusaurus'', ''Carcharodontosaurus'' and ''Tyrannotitan'' which are among the largest known predatory dinosaurs. While it originally contained a wide assortment of giant theropods that were not closely related, the group has since been defined to encompass only the allosaurs and their closest kin. However, with the description and publication in 2019 of ''Asfaltovenator vialidadi'', a basal allosauroid curiously displaying both primitive and derived features seen in Tetanurae, the new phylogenetic analysis has found Megalosauroidea to be a basal grade of carnosaurs in respect to Allosauroidea; thus significantly expanding Carnosauria's inclusiveness towards its original context. Distinctive characteristics of carnosaurs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maxilla
The maxilla (plural: ''maxillae'' ) in vertebrates is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. The two maxillary bones are fused at the intermaxillary suture, forming the anterior nasal spine. This is similar to the mandible (lower jaw), which is also a fusion of two mandibular bones at the mandibular symphysis. The mandible is the movable part of the jaw. Structure In humans, the maxilla consists of: * The body of the maxilla * Four processes ** the zygomatic process ** the frontal process of maxilla ** the alveolar process ** the palatine process * three surfaces – anterior, posterior, medial * the Infraorbital foramen * the maxillary sinus * the incisive foramen Articulations Each maxilla articulates with nine bones: * two of the cranium: the frontal and ethmoid * seven of the face: the nasal, zygomatic, lacrimal, inferior n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synapomorphy
In phylogenetics, an apomorphy (or derived trait) is a novel character or character state that has evolved from its ancestral form (or plesiomorphy). A synapomorphy is an apomorphy shared by two or more taxa and is therefore hypothesized to have evolved in their most recent common ancestor. ) In cladistics, synapomorphy implies homology. Examples of apomorphy are the presence of erect gait, fur, the evolution of three middle ear bones, and mammary glands in mammals but not in other vertebrate animals such as amphibians or reptiles, which have retained their ancestral traits of a sprawling gait and lack of fur. Thus, these derived traits are also synapomorphies of mammals in general as they are not shared by other vertebrate animals. Etymology The word —coined by German entomologist Willi Hennig—is derived from the Ancient Greek words (''sún''), meaning "with, together"; (''apó''), meaning "away from"; and (''morphḗ''), meaning "shape, form". Clade analysis T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allosauroidea
Allosauroidea is a superfamily or clade of theropod dinosaurs which contains four family (biology), 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carcharodontosauridae
Carcharodontosauridae (carcharodontosaurids; from the Greek καρχαροδοντόσαυρος, ''carcharodontósauros'': "shark-toothed lizards") is a group of carnivorous theropod dinosaurs. In 1931, Ernst Stromer named Carcharodontosauridae as a family, which, in modern paleontology, indicates a clade within Carnosauria. Carcharodontosaurids include some of the largest land predators ever known: ''Giganotosaurus'', ''Mapusaurus'', ''Carcharodontosaurus'', and ''Tyrannotitan'' all rivaled or exceeded ''Tyrannosaurus'' in size. A 2015 paper by Christophe Hendrickx and colleagues gives a maximum length estimate of for the largest carcharodontosaurids, while the smallest carcharodontosaurids were estimated to have been at least long. Evolution Along with the spinosaurids, carcharodontosaurids were the largest predators in the early and middle Cretaceous throughout Gondwana, with species also present in North America (''Acrocanthosaurus''), Europe (''Concavenator'') and Asia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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