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Tochisaurus
''Tochisaurus'' (meaning "Ostrich lizard") is a genus of small troodontid theropod dinosaur from the Late Cretaceous Period of Mongolia. The type (and only named) species is ''Tochisaurus nemegtensis''. In 1948, a Soviet-Mongolian expedition found the remains of a small theropod in the Gobi Desert near Nemegt. In 1987 the find was reported by Sergei Kurzanov and later that year discussed by Halszka Osmólska who suggested it could represent a specimen of the troodontid ''Borogovia''. Later Osmólska understood it was a species new to science. It was formalized by Kurzanov and Osmólska in 1991 as ''Tochisaurus nemegtensis''. The generic name is derived from Mongolian ''toch, "ostrich", in reference to the fact that the foot, like with that bird, is functionally didactyl, i.e. has only two weight-bearing toes. The specific name refers to the Nemegt.Kurzanov S.M., and Osmólska, H., 1991, "''Tochisaurus nemegtensis'' gen. et sp. n., a new troodontid (Dinosauria, Theropoda) from M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Timeline Of Troodontid Research
This timeline of troodontid research is a chronological listing of events in the History of paleontology, history of paleontology focused on the troodontids, a group of bird-like theropod dinosaurs including animals like ''Troodon''. Troodontid remains were among the first dinosaur fossils to be reported from North America after paleontologists began performing research on the continent, specifically the genus ''Troodon'' itself. Since the type specimen of this genus was only a tooth and ''Troodon'' teeth are unusually similar to those of the unrelated thick-headed pachycephalosaurs, ''Troodon'' and its relatives would be embroiled in taxonomic confusion for over a century. ''Troodon'' was finally recognized as distinct from the pachycephalosaurs by Phil Currie in 1987 in paleontology, 1987. By that time many other species now recognized as troodontid had been discovered but had been classified in the family Saurornithoididae. Since these families were the same but the Troodontidae ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Troodontid
Troodontidae is a clade of bird-like theropod dinosaurs from the Late Jurassic to Late Cretaceous. During most of the 20th century, troodontid fossils were few and incomplete and they have therefore been allied, at various times, with many dinosaurian lineages. More recent fossil discoveries of complete and articulated specimens (including specimens which preserve feathers, eggs, embryos, and complete juveniles), have helped to increase understanding about this group. Anatomical studies, particularly studies of the most primitive troodontids, like '' Sinovenator'', demonstrate striking anatomical similarities with ''Archaeopteryx'' and primitive dromaeosaurids, and demonstrate that they are relatives comprising a clade called Paraves. Evolution The oldest definitive troodontid known is '' Hesperornithoides'' from the Late Jurassic of Wyoming. The slightly older '' Koparion'' of Utah is only represented by a single tooth, and small maniraptoran teeth from the Middle Jurassic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nemegt Formation
The Nemegt Formation (also known as Nemegtskaya Svita) is a geological formation in the Gobi Desert of Mongolia, dating to the Late Cretaceous. The formation consists of river channel sediments and contains fossils of fish, turtles, crocodilians, and a diverse fauna of dinosaurs, including birds. Description The Nemegt Formation is composed of mudstones and sandstones that were deposited by ancient lakes, streams, and flood plains. The Altan Uul locality was described by Michael Novacek as "a canyon carved out of a very rich series of sedimentary rocks" with "steep cliffs and narrow washes". The climate associated with it was wetter than when preceding formations were deposited; there seems to have existed at least some degree of forest cover as indicated by petrified fossil trunks. When examined, the rock facies of the upper section consist of braided meanders, and oxbow lakes. Alteration of sediment grades indicates frequent hydrodynamic condition changes (seasonal rain). Si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Halszka Osmólska
Halszka Osmólska (September 15, 1930 – March 31, 2008) was a Polish paleontologist who had specialized in Mongolian dinosaurs. Early life, family and education Osmólska was born in 1930 in Poznań. In 1949, she began to study biology at Faculty of Biology and Earth Sciences of the University of Poznań. Thereafter, she studied at the University of Warsaw, graduating in 1955. Career Osmólska worked at the Institute of Paleobiology of the Polish Academy of Sciences (PAN). Between 1983 and 1988, she served as the institute's director. She was a member of the Polish–Mongolian expeditions to the Gobi Desert (1963–1965, 1967–1971), and she described many finds from these rocks, often with Teresa Maryańska. Among the dinosaurs she described: * '' Deinocheirus'' (1967), with Ewa Roniewicz * '' Gallimimus'' (1972), with Roniewicz and Rinchen Barsbold * '' Pachycephalosauria'' (1974), with Maryańska * ''Bagaceratops'' (1975), with Maryańska * '' Barsboldia'' (1981) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Borogovia
''Borogovia'' is a troodontid theropod dinosaur genus which lived during the Late Cretaceous Period, in what is now Mongolia. It contains one species, ''Borogovia gracilicrus.'' Discovery and naming In 1971, a Polish-Mongolian expedition discovered the remains of a small theropod at the Altan Uul IV site, in the Nemegt Basin of Ömnögovĭ province. In 1982, upon describing '' Hulsanpes perlei'', the find was reported by Halszka Osmólska and considered by her to be a possible specimen of '' Saurornithoides''.Osmólska, H., (1982), "''Hulsanpes perlei'' n.g.n.sp. (Deinonychosauria, Saurisichia, Dinosauria) from the Upper Cretaceous Barun Goyot Formation of Mongolia", ''Neues Jahrbuch für Geologie und Paläontologie, Monatshefte'' 1982(7): 440-448 Later she concluded that it represented a species new to science. In 1987, Osmólska named and described the type species ''Borogovia gracilicrus''. The generic name is derived from the fantasy creatures known as 'borogoves' i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Cretaceous
The Late Cretaceous (100.5–66 Ma) is the more recent of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the Latin word for the white limestone known as chalk. The chalk of northern France and the white cliffs of south-eastern England date from the Cretaceous Period. Climate During the Late Cretaceous, the climate was warmer than present, although throughout the period a cooling trend is evident. The tropics became restricted to equatorial regions and northern latitudes experienced markedly more seasonal climatic conditions. Geography Due to plate tectonics, the Americas were gradually moving westward, causing the Atlantic Ocean to expand. The Western Interior Seaway divided North America into eastern and western halves; Appalachia and Laramidia. India maintained a northward course towards Asia. In the Southern Hemisphere, Aus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Holotype
A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism 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 and mycology, an isotype is a duplicate of the holotype, generally pieces from the same individual plant or samples from the same genetic individual. A holotype is not necessarily "ty ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taxa Named By Halszka Osmólska
In biology, a taxon (back-formation from ''taxonomy''; : taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and given a particular ranking, especially if and when it is accepted or becomes established. It is very common, however, for taxonomists to remain at odds over what belongs to a taxon and the criteria used for inclusion, especially in the context of rank-based (" Linnaean") nomenclature (much less so under phylogenetic nomenclature). If a taxon is given a formal scientific name, its use is then governed by one of the nomenclature codes specifying which scientific name is correct for a particular grouping. Initial attempts at classifying and ordering organisms (plants and animals) were presumably set forth in prehistoric times by hunter-gatherers, as suggested by the fairly sophisticated folk taxonomies. Much later, Aristotle, and later still ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maastrichtian Dinosaurs
The Maastrichtian ( ) is, in the International Commission on Stratigraphy (ICS) geologic timescale, the latest age (uppermost stage) of the Late Cretaceous Epoch or Upper Cretaceous Series, the Cretaceous Period or System, and of the Mesozoic Era or Erathem. It spanned the interval from . The Maastrichtian was preceded by the Campanian and succeeded by the Danian (part of the Paleogene and Paleocene). It is named after the city of Maastricht, the capital and largest city of the Limburg province in the Netherlands. The Cretaceous–Paleogene extinction event (formerly known as the Cretaceous–Tertiary extinction event) occurred at the end of this age. In this mass extinction, many commonly recognized groups such as non-avian dinosaurs, plesiosaurs and mosasaurs, as well as many other lesser-known groups, died out. The cause of the extinction is most commonly linked to an asteroid about wide colliding with Earth, ending the Cretaceous. Stratigraphic definitions Definition ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dinosaur Genera
Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic Geological period, period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the #Evolutionary history, evolution of dinosaurs is a subject of active research. They became the dominant terrestrial vertebrates after the Triassic–Jurassic extinction event 201.3 mya and their dominance continued throughout the Jurassic and Cretaceous periods. The fossil record shows that birds are feathered dinosaurs, Evolution of birds, having evolved from earlier Theropoda, 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 taxonomy (biology), taxonomic, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
