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Jinzhousaurus
''Jinzhousaurus'' is a genus of hadrosauroid dinosaur of the Early Cretaceous of China. The type species is ''Jinzhousaurus yangi''. The generic name refers to the town Jinzhou. The specific name honours Yang Zhongjian as the founder of Chinese paleontology. It was first described by Wang Xiao-lin and Xu Xing in 2001. Discovery Its fossil, holotype IVPP V12691, was found near Baicaigou in Yixian County in the Dawangzhangzi Beds of the Yixian Formation in Liaoning, China, having an oldest determinable age of 122 million years, during the early Aptian stage of the early Cretaceous Period.Zhou, Z. (2006). "Evolutionary radiation of the Jehol Biota: chronological and ecological perspectives." ''Geological Journal'', 41: 377-393. It consists of a nearly complete skeleton, compressed on a slab. Description ''Jinzhousaurus'' has a length of about 7 metres (23 ft) and its skull is about half a metre long. Its snout was elongated with large nares and lacking an antorbi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jinzhousaurus
''Jinzhousaurus'' is a genus of hadrosauroid dinosaur of the Early Cretaceous of China. The type species is ''Jinzhousaurus yangi''. The generic name refers to the town Jinzhou. The specific name honours Yang Zhongjian as the founder of Chinese paleontology. It was first described by Wang Xiao-lin and Xu Xing in 2001. Discovery Its fossil, holotype IVPP V12691, was found near Baicaigou in Yixian County in the Dawangzhangzi Beds of the Yixian Formation in Liaoning, China, having an oldest determinable age of 122 million years, during the early Aptian stage of the early Cretaceous Period.Zhou, Z. (2006). "Evolutionary radiation of the Jehol Biota: chronological and ecological perspectives." ''Geological Journal'', 41: 377-393. It consists of a nearly complete skeleton, compressed on a slab. Description ''Jinzhousaurus'' has a length of about 7 metres (23 ft) and its skull is about half a metre long. Its snout was elongated with large nares and lacking an antorbi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hadrosauroidea
Hadrosauroidea is a clade or superfamily of ornithischian dinosaurs that includes the "duck-billed" dinosaurs, or hadrosaurids, and all dinosaurs more closely related to them than to ''Iguanodon''. Their remains have been recovered in Asia, Europe, Africa and the Americas. Many primitive hadrosauroids, such as the Asian ''Probactrosaurus'' and ''Altirhinus'', have traditionally been included in a paraphyly, paraphyletic (unnatural grouping) "Iguanodontidae". With cladistics, cladistic analysis, the traditional Iguanodontidae has been largely disbanded, and probably includes only ''Iguanodon'' and perhaps its closest relatives. Classification The cladogram below follows an analysis by Andrew McDonald, 2012, and shows the position of Hadrosauroidea within Styracosterna. The cladogram below follows an analysis by Wu Wenhao and Pascal Godefroit (2012). Cladogram after Prieto-Marquez and Norell (2010). A phylogenetic analysis performed by Ramírez-Velasco ''et al.'' (2012) foun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iguanodontidae
Iguanodontidae is a family of iguanodontians belonging to Styracosterna, a derived clade within Ankylopollexia. Characterized by their elongated maxillae, they were herbivorous and typically large in size. This family exhibited locomotive dynamism; there exists evidence for both bipedalism and quadrupedalism within iguanodontid species, supporting the idea that individual organisms were capable of both locomoting exclusively with their hind limbs and locomoting quadrupedally. Iguanodontids possess hoof-like second, third, and fourth digits, and in some cases, a specialized thumb spike and an opposable fifth digit. Their skull construction allows for a strong chewing mechanism called a transverse power stroke. This, paired with their bilateral dental occlusion, made them extremely effective as herbivores. Members of Iguanodontidae are thought to have had a diet that consisted of both gymnosperms and angiosperms, the latter of which co-evolved with the iguanodontids in the Cretac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iguanodontoidea
Iguanodontidae is a family of iguanodontians belonging to Styracosterna, a derived clade within Ankylopollexia. Characterized by their elongated maxillae, they were herbivorous and typically large in size. This family exhibited locomotive dynamism; there exists evidence for both bipedalism and quadrupedalism within iguanodontid species, supporting the idea that individual organisms were capable of both locomoting exclusively with their hind limbs and locomoting quadrupedally. Iguanodontids possess hoof-like second, third, and fourth digits, and in some cases, a specialized thumb spike and an opposable fifth digit. Their skull construction allows for a strong chewing mechanism called a transverse power stroke. This, paired with their bilateral dental occlusion, made them extremely effective as herbivores. Members of Iguanodontidae are thought to have had a diet that consisted of both gymnosperms and angiosperms, the latter of which co-evolved with the iguanodontids in the Cretace ... [...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] |
Antorbital Fenestra
An antorbital fenestra (plural: fenestrae) is an opening in the skull that is in front of the eye sockets. This skull character is largely associated with archosauriforms, first appearing during the Triassic Period. Among extant archosaurs, birds still possess antorbital fenestrae, whereas crocodylians have lost them. The loss in crocodylians is believed to be related to the structural needs of their skulls for the bite force and feeding behaviours that they employ.Preushscoft, H., Witzel, U. 2002. Biomechanical Investigations on the Skulls of Reptiles and Mammals. Senckenbergiana Lethaea 82:207–222.Rayfield, E.J., Milner, A.C., Xuan, V.B., Young, P.G. 2007. Functional Morphology of Spinosaur "Crocodile Mimic" Dinosaurs. JVP. 27(4):892–901. In some archosaur species, the opening has closed but its location is still marked by a depression, or fossa, on the surface of the skull called the antorbital fossa. The antorbital fenestra houses a paranasal sinus that is confluent with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aptian
The Aptian is an age in the geologic timescale or a stage in the stratigraphic column. It is a subdivision of the Early or Lower Cretaceous Epoch or Series and encompasses the time from 121.4 ± 1.0 Ma to 113.0 ± 1.0 Ma (million years ago), approximately. The Aptian succeeds the Barremian and precedes the Albian, all part of the Lower/Early Cretaceous. The Aptian partly overlaps the upper part of the Western European Urgonian Stage. The Selli Event, also known as OAE1a, was one of two oceanic anoxic events in the Cretaceous Period, which occurred around 120 Ma and lasted approximately 1 to 1.3 million years. The Aptian extinction was a minor extinction event hypothesized to have occurred around 116 to 117 Ma.Archangelsky, Sergio.The Ticó Flora (Patagonia) and the Aptian Extinction Event" ''Acta Paleobotanica'' 41(2), 2001, pp. 115-22. Stratigraphic definitions The Aptian was named after the small city of Apt in the Provence region of France, which is also known for its cry ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of the entire Phanerozoic. The name is derived from the Latin ''creta'', "chalk", which is abundant in the latter half of the period. It is usually abbreviated K, for its German translation ''Kreide''. The Cretaceous was a period with a relatively warm climate, resulting in high eustatic sea levels that created numerous shallow inland seas. These oceans and seas were populated with now- extinct marine reptiles, ammonites, and rudists, while dinosaurs continued to dominate on land. The world was ice free, and forests extended to the poles. During this time, new groups of mammals and birds appeared. During the Early Cretaceous, flowering plants appeared and began to rapidly diversify, becoming the dominant group of plants across the Earth b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 Kerguelen P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dentary
In anatomy, the mandible, lower jaw or jawbone is the largest, strongest and lowest bone in the human facial skeleton. It forms the lower jaw and holds the lower tooth, teeth in place. The mandible sits beneath the maxilla. It is the only movable bone of the skull (discounting the ossicles of the middle ear). It is connected to the temporal bones by the temporomandibular joints. The bone is formed prenatal development, in the fetus from a fusion of the left and right mandibular prominences, and the point where these sides join, the mandibular symphysis, is still visible as a faint ridge in the midline. Like other symphyses in the body, this is a midline articulation where the bones are joined by fibrocartilage, but this articulation fuses together in early childhood.Illustrated Anatomy of the Head and Neck, Fehrenbach and Herring, Elsevier, 2012, p. 59 The word "mandible" derives from the Latin word ''mandibula'', "jawbone" (literally "one used for chewing"), from ''wikt:mandere ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paraphyletic
In taxonomy (general), taxonomy, a group is paraphyletic if it consists of the group's most recent common ancestor, last common ancestor and most of its descendants, excluding a few Monophyly, 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 Synapomorphy and apomorphy, synapomorphies and symplesiomorphy, 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 a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
