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Xixiaichthys
''Xixiaichthys'' is an extinct genus of osteoglossiform fish that lived in China during the Early Cretaceous and was found in the Madongshan Formation and also the Xinminbao Group. The type species is ''Xixiaichthys tongxiensis'' and is based on the holotype (specimen V 13114.1), a complete skeleton,Zhang, J. (2004). New Fossil Osteoglossomorph from Ningxia, China. ''Journal of Vertebrate Paleontology'' 24(3):515-524 and several other specimens of varying completeness. Kim ''et al.'' (2022) compared a fish centrum found with the holotype of the theropod dinosaur ''Raptorex ''Raptorex'' is a dubious genus of tyrannosaurid dinosaur. Its fossil remains consist of a single juvenile specimen probably uncovered in Mongolia, or possibly northeastern China. The type species is ''R. kriegsteini'', described in 2009 by Se ... kriegsteini'' with '' Harenaichthys lui'' and ''Xixiaichthys tongxinensis'', and interpreted their findings as supporting the conclusion that the holotype of ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xinminbao Group
The Xīnmínbǎo Group () is a group of geological formations in north central China. They occur across a large depression between the Altai mountains of Mongolia to the north and the Qilian mountains of the Qinghai Plateau to the south, in the Gōngpóquán (公婆泉) and Suànjǐngzi (算井子) basins, and also in the neighbouring Jiuquan Basin. Both of these areas are inland basins consisting of fluvial (river), lacustrine (lake), and intermontane (between mountains) alluvial fan (floodplain) sediments that were deposited during the Early Cretaceous, probably during the Aptian or possibly late Barremian stage, when the climate was semi-arid and subtropical. The group has been visited by many expeditions including the Silk Road dinosaur expedition of 1992 which concentrated on the area around Mazong Shan. Geology The group is made up of three main formations. Chijinbao Formation This consists of a lower red unit of coarse conglomerates grading to fine sandstones r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Raptorex
''Raptorex'' is a dubious genus of tyrannosaurid dinosaur. Its fossil remains consist of a single juvenile specimen probably uncovered in Mongolia, or possibly northeastern China. The type species is ''R. kriegsteini'', described in 2009 by Sereno and colleagues. The genus name is derived from Latin ', "robber", and ', "king". The specific name honours Roman Kriegstein, a survivor of the Holocaust, whose son Henry Kriegstein donated the specimen to the University of Chicago for scientific study. While initially considered to have come from the Yixian Formation of China, dated to approximately 125 million years ago during the early Cretaceous period, later studies showed that such an early date for the fossil are unlikely, and given its extremely close similarity to juvenile tyrannosaurids of the late Cretaceous, it probably came from the Nemegt or similar formation. Because the specimen is a juvenile, and the changes undergone by tyrannosaurids during growth are not yet well ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Harenaichthys
''Harenaichthys'' is an extinct genus of osteoglossiform fish that lived in Mongolia during the Late Cretaceous and was found in the Nemegt Formation. The type species is ''H. lui'' and is based solely on the holotype, which consists of partial skull parts, isolated and articulated centra, and an articulated caudal fin preserved together within a single sandstone block. The monospecific assemblages of ''Harenaichthys'' were affected by the high altitude of their habitat and the fossils show signs of pathologies caused by diseases while the animals were still alive. Kim ''et al.'' (2022) compared a fish centrum found with the holotype of the theropod dinosaur ''Raptorex kriegsteini'' with ''Harenaichthys lui'' and ''Xixiaichthys ''Xixiaichthys'' is an extinct genus of osteoglossiform fish that lived in China during the Early Cretaceous and was found in the Madongshan Formation and also the Xinminbao Group. The type species is ''Xixiaichthys tongxiensis'' and is based o ... t ... [...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 Kergue ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Osteoglossiformes
Osteoglossiformes (Greek: "bony tongues") is a relatively primitive order of ray-finned fish that contains two sub-orders, the Osteoglossoidei and the Notopteroidei. All of at least 245 living species inhabit freshwater. They are found in South America, Africa, Australia and southern Asia, having first evolved in Gondwana before that continent broke up. In 2008 several new species of marine osteoglossiforms was described from the Danish Eocene Fur Formation dramatically increases the diversity of this group. This implies that the Osteoglossomorpha is not a primary freshwater fish group with the osteoglossiforms having a typical Gondwana distribution. The Gymnarchidae (the only species being '' Gymnarchus niloticus'', the African knifefish) and the Mormyridae are weakly electric fish able to sense their prey using electric fields. The mooneyes ( Hiodontidae) are often classified here, but may also be placed in a separate order, Hiodontiformes. Members of the order are no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
China
China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's List of countries and dependencies by population, most populous country, with a Population of China, population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and Borders of China, borders fourteen countries by land, the List of countries and territories by land borders, most of any country in the world, tied with Russia. Covering an area of approximately , it is the world's third List of countries and dependencies by area, largest country by total land area. The country consists of 22 provinces of China, provinces, five autonomous regions of China, autonomous regions, four direct-administered municipalities of China, municipalities, and two special administrative regions of China, Special Administrative Regions (Hong Kong and Macau). The national capital is Beijing, and the List of cities in China by population, most populous cit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Holotype
A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several examples, but explicitly designated as the holotype. Under the International Code of Zoological Nomenclature (ICZN), a holotype is one of several kinds of name-bearing types. In the International Code of Nomenclature for algae, fungi, and plants (ICN) and ICZN, the definitions of types are similar in intent but not identical in terminology or underlying concept. For example, the holotype for the butterfly '' Plebejus idas longinus'' is a preserved specimen of that subspecies, held by the Museum of Comparative Zoology at Harvard University. In botany, an isotype is a duplicate of the holotype, where holotype and isotypes are often pieces from the same individual plant or samples from the same gathering. A holotype is not necessaril ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theropod
Theropoda (; ), whose members are known as theropods, is a dinosaur clade that is characterized by hollow bones and three toes and claws on each limb. Theropods are generally classed as a group of saurischian dinosaurs. They were ancestrally carnivorous, although a number of theropod groups evolved to become herbivores and omnivores. Theropods first appeared during the Carnian age of the late Triassic period 231.4 million years ago ( Ma) and included all the large terrestrial carnivores from the Early Jurassic until at least the close of the Cretaceous, about 66 Ma. In the Jurassic, birds evolved from small specialized coelurosaurian theropods, and are today represented by about 10,500 living species. Biology Diet and teeth Theropods exhibit a wide range of diets, from insectivores to herbivores and carnivores. Strict carnivory has always been considered the ancestral diet for theropods as a group, and a wider variety of diets was historically considered a ch ... [...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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Osteoglossiformes
Osteoglossiformes (Greek: "bony tongues") is a relatively primitive order of ray-finned fish that contains two sub-orders, the Osteoglossoidei and the Notopteroidei. All of at least 245 living species inhabit freshwater. They are found in South America, Africa, Australia and southern Asia, having first evolved in Gondwana before that continent broke up. In 2008 several new species of marine osteoglossiforms was described from the Danish Eocene Fur Formation dramatically increases the diversity of this group. This implies that the Osteoglossomorpha is not a primary freshwater fish group with the osteoglossiforms having a typical Gondwana distribution. The Gymnarchidae (the only species being '' Gymnarchus niloticus'', the African knifefish) and the Mormyridae are weakly electric fish able to sense their prey using electric fields. The mooneyes ( Hiodontidae) are often classified here, but may also be placed in a separate order, Hiodontiformes. Members of the order are no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fossil Taxa Described In 2004
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in amber, hair, petrified wood and DNA remnants. The totality of fossils is known as the ''fossil record''. Paleontology is the study of fossils: their age, method of formation, and evolutionary significance. Specimens are usually considered to be fossils if they are over 10,000 years old. The oldest fossils are around 3.48 billion years old to 4.1 billion years old. Early edition, published online before print. The observation in the 19th century that certain fossils were associated with certain rock strata led to the recognition of a geological timescale and the relative ages of different fossils. The development of radiometric dating techniques in the early 20th century allowed scientists to quantitatively measure the absolut ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
