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Proceratosauridae
Proceratosauridae is a family or clade of tyrannosauroid theropod dinosaurs from the Middle Jurassic to the Early Cretaceous. Distinguishing features Unlike the advanced tyrannosaurids but similar to primitive tyrannosauroids like ''Dilong'', proceratosaurids were generally small (with the exception of the possible proceratosaurids '' Yutyrannus'' and '' Sinotyrannus'') and had fairly long, three-fingered arms capable of grasping prey. In comparison to other members of Tyrannosauroidea, proceratosaurids can be distinguished by the following features according to phylogenetic analyses by Averianov ''et al''. (2010) and Loewen ''et al''. (2013) : * A sagittal cranial crest formed by the nasals starting at the junction of the premaxilla and nasals. * Extremely elongated external nares, with posterior margins posterior to the anterior margin of the antorbital fossa and maxillary fenestrae. * A short ventral margin of the premaxilla. * The depth of the antorbital fossa ventral to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sinotyrannus
''Sinotyrannus'' (meaning "Chinese tyrant") is a genus of large basal tyrannosauroid dinosaur, known from a single incomplete fossil specimen including a partial skull, from the Early Cretaceous Jiufotang Formation of Liaoning, China. Specifically, it is a member of the Proceratosauridae, a family that originated in the Jurassic whose members are known from Europe and Asia. Though it is not much younger than primitive tyrannosauroids such as ''Dilong'', it is similar in size to later forms such as ''Tyrannosaurus''. It was much larger than contemporary tyrannosauroids, reaching a total estimated length of , and was the largest known theropod from the Jiufotang Formation. The type species is ''S. kazuoensis'', described by Ji ''et al.'', in 2009. Description ''Sinotyrannus'' was a large tyrannosaur, measuring long and weighing . It was among the largest basal tyrannosauroids known, repudiating the previously presumed trend that tyrannosauroids gradually increased in size thr ... [...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 subd ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Premaxilla
The premaxilla (or praemaxilla) is one of a pair of small cranial bones at the very tip of the upper jaw of many animals, usually, but not always, bearing teeth. In humans, they are fused with the maxilla. The "premaxilla" of therian mammal has been usually termed as the incisive bone. Other terms used for this structure include premaxillary bone or ''os premaxillare'', intermaxillary bone or ''os intermaxillare'', and Goethe's bone. Human anatomy In human anatomy, the premaxilla is referred to as the incisive bone (') and is the part of the maxilla which bears the incisor teeth, and encompasses the anterior nasal spine and alar region. In the nasal cavity, the premaxillary element projects higher than the maxillary element behind. The palatal portion of the premaxilla is a bony plate with a generally transverse orientation. The incisive foramen is bound anteriorly and laterally by the premaxilla and posteriorly by the palatine process of the maxilla. It is formed from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Velociraptorinae
Velociraptorinae is a subfamily of the theropod group Dromaeosauridae. The earliest velociraptorines are probably ''Nuthetes'' from the United Kingdom, and possibly ''Deinonychus'' from North America. However, several indeterminate velociraptorines have also been discovered, dating to the Kimmeridgian stage, in the Late Jurassic Period. These fossils were discovered in the Langenberg quarry, Oker near Goslar, Germany.van der Lubbe, T., Richter, U. and Knotschke, N. (2009).Velociraptorine dromaeosaurid teeth from the Kimmeridgian (Late Jurassic) of Germany" ''Acta Palaeontologica Polonica'', 54(3): 401-408. Description While most velociraptorines were generally small animals, at least one species may have achieved gigantic sizes comparable to those found among the dromaeosaurines. So far, this unnamed giant velociraptorine is known only from isolated teeth found on the Isle of Wight, England. The teeth belong to an animal the size of dromaeosaurines of the genus ''Utahraptor'', but ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dromaeosauridae
Dromaeosauridae () is a family of feathered theropod dinosaurs. They were generally small to medium-sized feathered carnivores that flourished in the Cretaceous Period. The name Dromaeosauridae means 'running lizards', from Greek ('), meaning 'runner', and ('), meaning 'lizard'. In informal usage, they are often called raptors (after ''Velociraptor''), a term popularized by the film ''Jurassic Park''; a few types include the term "raptor" directly in their name and have come to emphasize their bird-like appearance and speculated bird-like behavior. Dromaeosaurid fossils have been found across the globe in North America, Europe, Africa, Asia, South America and Antarctica, with some fossils giving credence to the possibility that they inhabited Australia as well. They first appeared in the mid-Jurassic Period (late Bathonian stage, about 167 million years ago) and survived until the end of the Cretaceous (Maastrichtian stage, 66 ma), existing until the Cretaceous–Paleogene ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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] |
Ornithomimus
''Ornithomimus'' (; "bird mimic") is a genus of ornithomimid dinosaurs from the Late Cretaceous Period of what is now North America. ''Ornithomimus'' was a swift bipedal theropod which fossil evidence indicates was covered in feathers, equipped with a small toothless beak that may indicate an omnivorous diet. It is usually classified into two species: the type species, ''Ornithomimus velox'', and a referred species, ''Ornithomimus edmontonicus''. ''O. velox'' was named in 1890 by Othniel Charles Marsh on the basis of a foot and partial hand from the late Maastrichtian-age Denver Formation of Colorado, United States. Another seventeen species have been named since, though most of them have subsequently been assigned to new genera or shown to be not directly related to ''Ornithomimus velox''. The best material of species still considered part of the genus has been found in Alberta, Canada, representing the species ''O. edmontonicus'', known from several skeletons from the early Ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coelurus
''Coelurus'' ( ) is a genus of coelurosaurian dinosaur from the Late Jurassic period (mid-late Kimmeridgian faunal stage, 155–152 million years ago). The name means "hollow tail", referring to its hollow tail vertebrae (Greek κοῖλος, ''koilos'' = hollow + οὐρά, ''oura'' = tail). Although its name is linked to one of the main divisions of theropods ( Coelurosauria), it has historically been poorly understood, and sometimes confused with its better-known contemporary '' Ornitholestes''. Like many dinosaurs studied in the early years of paleontology, it has had a confusing taxonomic history, with several species being named and later transferred to other genera or abandoned. Only one species is currently recognized as valid: the type species, ''C. fragilis'', described by Othniel Charles Marsh in 1879. It is known from one partial skeleton found in the Morrison Formation of Wyoming, United States. It was a small bipedal carnivore with elongate legs. Descrip ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compsognathus
''Compsognathus'' (; Greek ''kompsos''/κομψός; "elegant", "refined" or "dainty", and ''gnathos''/γνάθος; "jaw") is a genus of small, bipedal, carnivorous theropod dinosaur. Members of its single species ''Compsognathus longipes'' could grow to around the size of a turkey. They lived about 150 million years ago, during the Tithonian age of the late Jurassic period, in what is now Europe. Paleontologists have found two well-preserved fossils, one in Germany in the 1850s and the second in France more than a century later. Today, ''C. longipes'' is the only recognized species, although the larger specimen discovered in France in the 1970s was once thought to belong to a separate species and named ''C. corallestris''. Many presentations still describe ''Compsognathus'' as "chicken-sized" dinosaurs because of the size of the German specimen, which is now believed to be a juvenile. ''Compsognathus longipes'' is one of the few dinosaur species whose diet is known wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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] |
Type (zoology)
In biology, a type is a particular specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to anchor or centralizes the defining features of that particular taxon. In older usage (pre-1900 in botany), a type was a taxon rather than a specimen. A taxon is a scientifically named grouping of organisms with other like organisms, a set that includes some organisms and excludes others, based on a detailed published description (for example a species description) and on the provision of type material, which is usually available to scientists for examination in a major museum research collection, or similar institution. Type specimen According to a precise set of rules laid down in the International Code of Zoological Nomenclature (ICZN) and the International Code of Nomenclature for algae, fungi, and plants (ICN), the scientific name of every taxon is almost ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ilium (bone)
The ilium () (plural ilia) is the uppermost and largest part of the hip bone, and appears in most vertebrates including mammals and birds, but not bony fish. All reptiles have an ilium except snakes, although some snake species have a tiny bone which is considered to be an ilium. The ilium of the human is divisible into two parts, the body and the wing; the separation is indicated on the top surface by a curved line, the arcuate line, and on the external surface by the margin of the acetabulum. The name comes from the Latin (''ile'', ''ilis''), meaning "groin" or "flank". Structure The ilium consists of the body and wing. Together with the ischium and pubis, to which the ilium is connected, these form the pelvic bone, with only a faint line indicating the place of union. The body ( la, corpus) forms less than two-fifths of the acetabulum; and also forms part of the acetabular fossa. The internal surface of the body is part of the wall of the lesser pelvis and gives or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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