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Asfaltovenator Vialidadi
''Asfaltovenator'' (meaning "Cañadón Asfalto Formation hunter" after the fossil formation in which its fossils were found) is a genus of possibly allosauroid dinosaur from the Lower Jurassic Cañadón Asfalto Formation from Chubut Province, Argentina. The type species, type and only species is ''Asfaltovenator vialidadi''. Discovery In 2002, technician Leandro Canesa, roughly a mile north of Cerro Condor, discovered a theropod skeleton. Excavations started in 2005. In 2007, the fossil was in its entirety removed as an enormous stone block, covered by plaster of Paris. It was then prepared by Mariano Caffa, a process that took five years due to the extreme hardness of the stone matrix. Between 2013 and 2015, it was compared with the specimens of related theropods, researchers personally investigating their exemplars in collections all over the world. In 2019, the type species ''Asfaltovenator vialidadi'' was named and described by Oliver Walter Mischa Rauhut and Diego Pol. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toarcian
The Toarcian is, in the ICS' geologic timescale, an age and stage in the Early or Lower Jurassic. It spans the time between 182.7 Ma (million years ago) and 174.1 Ma. It follows the Pliensbachian and is followed by the Aalenian. The Toarcian Age began with the Toarcian turnover, the extinction event that sets its fossil faunas apart from the previous Pliensbachian age. It is believed to have ended with a global cooling event known as the Comptum Cooling Event, although whether it represented a worldwide event is controversial. Stratigraphic definitions The Toarcian takes its name from the city of Thouars, just south of Saumur in the Loire Valley of France. The stage was introduced by French palaeontologist Alcide d'Orbigny in 1842, after examining rock strata of this age in a quarry near Thouars. In Europe this period is represented by the upper part of the Lias. The base of the Toarcian is defined as the place in the stratigraphic record where the ammonite genus '' Eoda ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asfaltovenator Vialidadi
''Asfaltovenator'' (meaning "Cañadón Asfalto Formation hunter" after the fossil formation in which its fossils were found) is a genus of possibly allosauroid dinosaur from the Lower Jurassic Cañadón Asfalto Formation from Chubut Province, Argentina. The type species, type and only species is ''Asfaltovenator vialidadi''. Discovery In 2002, technician Leandro Canesa, roughly a mile north of Cerro Condor, discovered a theropod skeleton. Excavations started in 2005. In 2007, the fossil was in its entirety removed as an enormous stone block, covered by plaster of Paris. It was then prepared by Mariano Caffa, a process that took five years due to the extreme hardness of the stone matrix. Between 2013 and 2015, it was compared with the specimens of related theropods, researchers personally investigating their exemplars in collections all over the world. In 2019, the type species ''Asfaltovenator vialidadi'' was named and described by Oliver Walter Mischa Rauhut and Diego Pol. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megalosauridae
Megalosauridae is a monophyletic family of carnivorous theropod dinosaurs within the group Megalosauroidea. Appearing in the Middle Jurassic, megalosaurids were among the first major radiation of large theropod dinosaurs. They were a relatively primitive group of basal tetanurans containing two main subfamilies, Megalosaurinae and Afrovenatorinae, along with the basal genus ''Eustreptospondylus'', an unresolved taxon which differs from both subfamilies. The defining megalosaurid, ''Megalosaurus bucklandii'', was first named and described in 1824 by William Buckland after multiple finds in Stonesfield, Oxfordshire, UK. ''Megalosaurus'' was the first formally described dinosaur and was the basis for the establishment of the clade Dinosauria. It is also one of the largest known Middle Jurassic carnivorous dinosaurs, with the best-preserved femur at 805 mm and a proposed body mass of around 943 kg. Megalosauridae has mainly been recognized as a European group of dinosaurs, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spinosaurus Aegyptiacus
''Spinosaurus'' (; ) is a genus of spinosaurid dinosaur that lived in what now is North Africa during the Cenomanian to upper Turonian stages of the Late Cretaceous period, about 99 to 93.5 million years ago. The genus was known first from Egyptian remains discovered in 1912 and described by German palaeontologist Ernst Stromer in 1915. The original remains were destroyed in World War II, but additional material came to light in the early 21st century. It is unclear whether one or two species are represented in the fossils reported in the scientific literature. The best known species is ''S. aegyptiacus'' from Egypt, although a potential second species, ''S. maroccanus'', has been recovered from Morocco. The contemporary spinosaurid genus ''Sigilmassasaurus'' has also been synonymized by some authors with ''S. aegyptiacus'', though other researchers propose it to be a distinct taxon. Another possible junior synonym is ''Oxalaia'' from the Alcântara Formation in Brazil. ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spinosauridae
The Spinosauridae (or spinosaurids) are a clade or family of tetanuran theropod dinosaurs comprising ten to seventeen known genera. They came into prominence during the Cretaceous period. Spinosaurid fossils have been recovered worldwide, including Africa, Europe, South America and Asia. Their remains have generally been attributed to the Early to Mid Cretaceous. Spinosaurids were large bipedal carnivores. Their crocodilian-like skulls were long, low and narrow, bearing conical teeth with reduced or absent serrations. The tips of their upper and lower jaws fanned out into a spoon-shaped structure similar to a rosette, behind which there was a notch in the upper jaw that the expanded tip of the lower jaw fit into. The nostrils of spinosaurids were retracted to a position further back on the head than in most other theropods, and they had bony crests on their heads along the midline of their skulls. Their robust shoulders wielded stocky forelimbs, with three-fingered hands that b ... [...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] |
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 omniv ... [...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] |
Evolutionary Grade
A grade is a taxon united by a level of morphological or physiological complexity. The term was coined by British biologist Julian Huxley, to contrast with clade, a strictly phylogenetic unit. Definition An evolutionary grade is a group of species united by morphological or physiological traits, that has given rise to another group that has major differences from the ancestral condition, and is thus not considered part of the ancestral group, while still having enough similarities that we can group them under the same clade. The ancestral group will not be phylogenetically complete (i.e. will not form a clade), so will represent a paraphyletic taxon. In order to fully understand evolutionary grades, one must first get a better understanding of Phylogenetics, defined as "''In biology, is the study of the evolutionary history and relationships among individuals or groups of organisms (e.g. species, or populations). These relationships are discovered through phylogenetic i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paraphyly
In taxonomy, a group is paraphyletic if it consists of the group's last common ancestor and most of its descendants, excluding a few monophyletic subgroups. The group is said to be paraphyletic ''with respect to'' the excluded subgroups. In contrast, a monophyletic group (a clade) includes a common ancestor and ''all'' of its descendants. The terms are commonly used in phylogenetics (a subfield of biology) and in the tree model of historical linguistics. Paraphyletic groups are identified by a combination of synapomorphies and symplesiomorphies. If many subgroups are missing from the named group, it is said to be polyparaphyletic. The term was coined by Willi Hennig to apply to well-known taxa like Reptilia ( reptiles) which, as commonly named and traditionally defined, is paraphyletic with respect to mammals and birds. Reptilia contains the last common ancestor of reptiles and all descendants of that ancestor, including all extant reptiles as well as the extinct synapsids, ... [...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 all spec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Piatnitzkysauridae
Piatnitzkysauridae is an extinct family of megalosauroid or basal Allosauroid dinosaurs. It only consists of three known dinosaur genera: '' Condorraptor'', ''Marshosaurus'', and ''Piatnitzkysaurus.'' The most complete and well known member of this family is ''Piatnitzkysaurus'', which also gives the family its name. Description So far all known piatnitzkysaurids have only been found in Jurassic deposits of the western hemisphere/New world. ''Piatnitzkysaurus'' and ''Condorraptor'' hail from the Cañadón Asfalto Formation of Argentina, which has been dated from the Toarcian epoch of the Early Jurassic to the Bathonian epoch of the Middle Jurassic (approximately 179 to 168 million years ago). ''Marshosaurus'' was found in the Morrison Formation of the United States, which was dated to the Kimmeridgian epoch of the Late Jurassic. Piatnitzkysaurids were among the first large theropods present in South America, and are evidence for a radiation of basal tetanurans in the middle Jur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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