Neovenatorid
Neovenatoridae is a proposed clade of carcharodontosaurian dinosaurs uniting some primitive members of the group such as ''Neovenator'' with the Megaraptora, a group of theropods with controversial affinities. Other studies recover megaraptorans as basal coelurosaurs unrelated to carcharodontosaurs. Other theropods with uncertain affinities such as ''Gualicho'', ''Chilantaisaurus'' and ''Deltadromeus'' are also sometimes included. Classification Phylogenetic studies conducted by Benson, Carrano and Brusatte (2010) and Carrano, Benson and Sampson (2012) recovered the group Megaraptora as members of the Neovenatoridae. This would make neovenatorids the latest-surviving allosauroids; at least one megaraptoran, '' Orkoraptor'', lived near the end of the Mesozoic era, dating to the early Maastrichtian stage of the latest Cretaceous period, about 70 million years ago. On the other hand, Novas ''et al.'' (2012), while confirming that ''Neovenator'' was closely related to carcharodontos ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Siats
''Siats'' (/see-ats/) is an extinct genus of large theropod dinosaur known from the Late Cretaceous Cedar Mountain Formation of Utah, United States. It contains a single species, ''Siats meekerorum''. It was initially classified as a megaraptoran, a clade of large theropods with very controversial relationships. ''Siats'' may be a neovenatorid allosauroid, a coelurosaur of uncertain phylogenetic position, or a tyrannosauroid. Discovery ''Siats'' was first described in 2012 and named by Lindsay E. Zanno and Peter J. Makovicky in 2013 and the type species is ''Siats meekerorum''. The generic name is derived from the name of ''Siats'', a man-eating monster in the Ute mythology. The specific name ''meekerorum'' honors the late geologist John Caldwell Meeker who bequeathed a fund for the support of paleontological research, his widow Withrow Meeker and their daughter Lis Meeker, one of the volunteers in the research project. ''Siats'' is known from the holotype FMNH PR 2716, a ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Metriacanthosauridae
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. Diag ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Gualicho
''Gualicho'' (named in reference to the gualichu) is a genus of theropod dinosaur. The type species is ''Gualicho shinyae''. It lived in what is now northern Patagonia, on what was then a South American island continent split off from the supercontinent Gondwana. The fossils were found in the Huincul Formation, dating to the late Cenomanian-early Turonian age of the upper Cretaceous Period, around 91 million years ago. Discovery On 13 February 2007, Akiko Shinya, preparator of the Field Museum of Natural History, east of the Ezequiel Ramos Mexía Reservoir at the Rancho Violante, discovered the skeleton of a theropod new to science. In 2016, the specimen was named and described by Sebastián Apesteguía, Nathan D. Smith, Rubén Juárez Valieri and Peter J. Makovicky. The generic name is derived from the '' gualichu'', a demon of local folklore. The specific name honours Shinya as the animal's discoverer. The holotype, MPCN PV 0001, consists of a partial skeleton lacking th ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Megaraptor
''Megaraptor'' () is a genus of large theropod dinosaur that lived in the ages of the Late Cretaceous. Its fossils have been discovered in the Patagonian Portezuelo Formation of Argentina, South America. Initially thought to have been a giant dromaeosaur-like coelurosaur, it was classified as a neovenatorid allosauroid in previous phylogenies, but more recent phylogeny and discoveries of related megaraptoran genera has placed it as either a basal tyrannosauroid or a basal coelurosaur with some studies still considering it a neovenatorid. Description ''Megaraptor'' was initially described as a giant dromaeosaur, known primarily from a single claw (about 30 cm long) that resembled the sickle-shaped foot claw of dromaeosaurids. The discovery of a complete front limb, however, showed that this giant claw actually came from the first finger of the hand. In 2010, Gregory S. Paul estimated its length at , its weight at . The hands were unusually elongated, bearing sickle-sh ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Deltadromeus
''Deltadromeus'' (meaning "delta runner") is a genus of theropod dinosaur from Northern Africa. It had long, unusually slender hind limbs for its size, suggesting that it was a swift runner. The skull is not known. One fossil specimen of a single species (''D. agilis'', or "agile delta runner") has been described, found in the Kem Kem Beds, which date to the mid-Cretaceous Period (mid- Cenomanian age), about 95 million years ago. It may be a junior synonym of the contemporary '' Bahariasaurus''.Holtz, Thomas R. Jr. (2008) ''Dinosaurs: The Most Complete, Up-to-Date Encyclopedia for Dinosaur Lovers of All Ages'Supplementary Information/ref> The classification of ''Deltadromeus'' has been in flux since its original description. In 2016, a South American theropod known as '' Gualicho shinyae'' was found to possess many similarities with ''Deltadromeus''. Depending on the phylogenetic position of ''Gualicho'', ''Deltadromeus'' may have been a neovenatorid carnosaur, a tyrannosauro ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Megaraptora
Megaraptora is a clade of carnivorous tetanuran theropod dinosaurs with controversial relations to other theropods. Its derived members, the Megaraptoridae are noted for their elongated hand claws and proportionally large arms, which are usually reduced in size in other large theropods. Megaraptorans are incompletely known, and no complete megaraptoran skeleton has been found. However, they still possessed a number of unique features. Their forelimbs were large and strongly built, and the ulna bone had a unique shape in members of the family Megaraptoridae, a subset of megaraptorans which excludes ''Fukuiraptor'' and ''Phuwiangvenator''. The first two fingers were elongated, with massive curved claws, while the third finger was small. Megaraptoran skull material is very incomplete, but a juvenile ''Megaraptor'' described in 2014 preserved a portion of the snout, which was long and slender. Leg bones referred to megaraptorans were also quite slender and similar to those of coeluro ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Chilantaisaurus
''Chilantaisaurus'' (" lizard") is a genus of large theropod dinosaur, possibly a neovenatorid or a primitive coelurosaur, from the Late Cretaceous Ulansuhai Formation of China (Turonian age, about 92 million years ago). The type species, ''C. tashuikouensis'', was described by Hu in 1964. Description ''Chilantaisaurus'' was a large theropod, estimated as weighing between and . In 2010, Brusatte et al. estimated it to weigh , based on femur length measurements. However, considering that greater femoral circumference indicates the greater capacity to withstand greater locomotor loads (not greater body mass), the 2020 study moderated the body mass of the holotype at . It is estimated to be around to long. Classification Hu considered ''Chilantaisaurus'' to be a carnosaur related to ''Allosaurus'', though some subsequent studies suggested that it may be a spinosauroid, possibly a primitive member of the spinosaurid family (Sereno, 1998; Chure, 2000; Rauhut, 2001) because ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Deinonychus
''Deinonychus'' ( ; ) is a genus of Dromaeosauridae, dromaeosaurid Theropoda, theropod dinosaur with one described species, ''Deinonychus antirrhopus''. This species, which could grow up to long, lived during the early Cretaceous Period (geology), Period, about 115–108 million years ago (from the mid-Aptian to early Albian Stage (stratigraphy), stages). Fossils have been recovered from the U.S. states of Montana, Utah, Wyoming, and Oklahoma, in rocks of the Cloverly Formation, Cedar Mountain Formation and Antlers Formation, though teeth that may belong to ''Deinonychus'' have been found much farther east in Maryland. Paleontology, Paleontologist John Ostrom's study of ''Deinonychus'' in the late 1960s revolutionized the way scientists thought about dinosaurs, leading to the "dinosaur renaissance" and igniting the debate on whether dinosaurs were endotherm, warm-blooded or ectotherm, cold-blooded. Before this, the popular conception of dinosaurs had been one of plodding ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Allosaurus
''Allosaurus'' () is a genus of large carnosaurian theropod dinosaur that lived 155 to 145 million years ago during the Late Jurassic epoch ( Kimmeridgian to late Tithonian). The name "''Allosaurus''" means "different lizard" alluding to its unique (at the time of its discovery) concave vertebrae. It is derived from the Greek (') ("different, other") and (') ("lizard / generic reptile"). The first fossil remains that could definitively be ascribed to this genus were described in 1877 by paleontologist Othniel Charles Marsh. As one of the first well-known theropod dinosaurs, it has long attracted attention outside of paleontological circles. ''Allosaurus'' was a large bipedal predator. Its skull was light, robust and equipped with dozens of sharp, serrated teeth. It averaged in length for ''A. fragilis'', with the largest specimens estimated as being long. Relative to the large and powerful hindlimbs, its three-fingered forelimbs were small, and the body was ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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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 Argentina, ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Early Cretaceous
The Early Cretaceous (geochronological name) or the Lower Cretaceous ( chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 145 Ma to 100.5 Ma. Geology Proposals for the exact age of the Barremian-Aptian boundary ranged from 126 to 117 Ma until recently (as of 2019), but based on drillholes in Svalbard the defining early Aptian Oceanic Anoxic Event 1a (OAE1a) was carbon isotope dated to 123.1±0.3 Ma, limiting the possible range for the boundary to c. 122–121 Ma. There is a possible link between this anoxic event and a series of Early Cretaceous large igneous provinces (LIP). The Ontong Java- Manihiki- Hikurangi large igneous province, emplaced in the South Pacific at c. 120 Ma, is by far the largest LIP in Earth's history. The Ontong Java Plateau today covers an area of 1,860,000 km2. In the Indian Ocean another LIP began to form at c. 120 Ma, the Kergue ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Yangchuanosaurus NT (flipped)
''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. I ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |