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Urbacodon
''Urbacodon'' ("URBAC tooth") is a genus of troodontid dinosaur, a type of small carnivore. It lived in Uzbekistan during the early Late Cretaceous Period, about 95 million years ago. On 9 September 2004, a lower jaw of a small theropod was uncovered by Anton Sergeevich Rezwiy near Itemir in the IT-01 quarry. The type species, ''Urbacodon itemirensis'', was named by Alexandr Averianov and Hans-Dieter Sues in 2007. The first part of the generic name ''Urbacodon'' is an acronym, honouring the Uzbek, Russian, British, American and Canadian scientists who participated in its discovery. This acronym was combined with a Greek ὀδών, ''odon'', "tooth". The specific name refers to the provenance from Itemir. The name was based on the holotype ZIN PH 944/16, a single left dentary with preserved replacement teeth from the Cenomanian Dzharakuduk Formation. Averianov and Sues also identified teeth and other material, earlier described by Lev Nesov, as a ''Urbacodon'' sp. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xixiasaurus
''Xixiasaurus'' () is a genus of troodontid dinosaur that lived during the Late Cretaceous Period in what is now China. The only known specimen was discovered in Xixia County, Henan Province, in central China, and became the holotype of the new genus and species ''Xixiasaurus henanensis'' in 2010. The names refer to the areas of discovery, and can be translated as "Henan Xixia lizard". The specimen consists of an almost complete skull (except for the hindmost portion), part of the lower jaw, and teeth, as well as a partial right forelimb. ''Xixiasaurus'' is estimated to have been long and to have weighed . As a troodontid, it would have been bird-like and lightly built, with grasping hands and an enlarged sickle-shaped claw on the second toe. Its skull was long, with a long, low snout that formed a tapering U-shape when seen from below. The of the forehead was dome-like in side view, which indicates it had an enlarged . It differed from other troodontids in that the front of th ... [...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] |
Troodontidae
Troodontidae is a clade of bird-like theropod dinosaurs. 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. Description Troodontids are a group of small, bird-like, gracile maniraptorans. All troodontids have unique features of the skull, such as large numbers of closely spaced teeth in the lower jaw. Troodontids have sickle-claws and raptorial hands, and some of the highest non-avian enceph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Troodontids
Troodontidae is a clade of bird-like theropod dinosaurs. 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. Description Troodontids are a group of small, bird-like, gracile maniraptorans. All troodontids have unique features of the skull, such as large numbers of closely spaced teeth in the lower jaw. Troodontids have sickle-claws and raptorial hands, and some of the highest non-avian encephaliza ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hans-Dieter Sues
Hans-Dieter Sues (born January 13, 1956) is a German-born American paleontologist who is Senior Scientist and Curator of Vertebrate Paleontology at the National Museum of Natural History of the Smithsonian Institution in Washington, DC. He received his education at Johannes Gutenberg-Universität Mainz (University of Mainz), University of Alberta, and Harvard University (Ph.D., 1984). Before assuming his present position, Sues worked at the Royal Ontario Museum and the University of Toronto and at the Carnegie Museum of Natural History in Pittsburgh. He is interested in the diversity, paleoecology, and evolutionary history of Paleozoic and Mesozoic tetrapods, especially archosaurian reptiles and cynodont therapsids, and the history of biology and paleontology. Sues has discovered numerous new dinosaurs and other extinct terrestrial vertebrates in Paleozoic and Mesozoic continental strata in North America and Europe. He has authored or co-authored over 150 articles and book chapte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bissekty Formation
The Bissekty Formation (sometimes referred to as Bissekt) is a geologic formation and Lagerstätte which crops out in the Kyzyl Kum desert of Uzbekistan, and dates to the Late Cretaceous Period. Laid down in the mid to late Turonian, it is dated to about 92 to 90 Ma (million years ago). Description The lithology of the sediment largely consists of cross bedded sandstones with interbeds of massive sandstone, well cemented intraformational conglomerate, siltstones and mudstones. Most of the fossils are found as clasts within the conglomerates. Fossil content The Bissekty Formation is characterised by a mix of marine, brackish, freshwater, and terrestrial animal fossils. This stands in contrast the strictly marine fossils found in the underlying Dzheirantui Formation, and indicates that the Bissekty was formed during the regression of a saltwater sea. The coastline expanded inland again in the upper portion of the Bissekty, represented by a proportional increase of fully aquat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lev Nesov
Lev may refer to: Common uses * Bulgarian lev, the currency of Bulgaria *an abbreviation for Leviticus, the third book of the Hebrew Bible and the Torah People and fictional characters * Lev (given name) *Lev (surname) Places *Lev, Azerbaijan, a village * Lev (crater), a tiny lunar crater LEV *Laborious Extra-Orbital Vehicle, a mecha from the video game ''Zone of the Enders'' *Lay eucharistic visitor, an extraordinary minister of Holy Communion approved by a church (usually Episcopalian or Lutheran) to bring Communion to the homebound *Libreria Editrice Vaticana, the Vatican Publishing House *Light electric vehicle, an electric bicycle * Local exhaust ventilation, the process of "changing" or replacing air to improve indoor air quality *Low emission vehicle, a motor vehicle that emits relatively low levels of motor vehicle emissions *Lunar Excursion Vehicle, an early name for the Apollo Lunar Module *Longevity escape velocity, a hypothetical situation wherein the average huma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cladistic
Cladistics (; ) is an approach to biological classification in which organisms are categorized in groups (" clades") based on hypotheses of most recent common ancestry. The evidence for hypothesized relationships is typically shared derived characteristics ( synapomorphies'')'' that are not present in more distant groups and ancestors. However, from an empirical perspective, common ancestors are inferences based on a cladistic hypothesis of relationships of taxa whose character states can be observed. Theoretically, a last common ancestor and all its descendants constitute a (minimal) clade. Importantly, all descendants stay in their overarching ancestral clade. For example, if the terms ''worms'' or ''fishes'' were used within a ''strict'' cladistic framework, these terms would include humans. Many of these terms are normally used paraphyletically, outside of cladistics, e.g. as a 'grade', which are fruitless to precisely delineate, especially when including extinct species. R ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saurornithoides
''Saurornithoides'' ( ) is a genus of troodontid maniraptoran dinosaur, which lived during the Late Cretaceous period. These creatures were predators, which could run fast on their hind legs and had excellent sight and hearing. The name is derived from the Greek stems ''saur~'' (lizard), ''ornith~'' (bird) and ''eides'' (form), referring to its bird-like skull. Description ''Saurornithoides'' is a member of the troodontids, a group of small, bird-like, gracile maniraptorans. All troodontids have many unique features of the skull, such as closely spaced teeth in the lower jaw, and large numbers of teeth. Troodontids have sickle-claws and raptorial hands, and some of the highest non-avian encephalization quotients, meaning they were behaviourally advanced and had keen senses. ''Saurornithoides'' was a rather small troodontid. Though a possible adult, the type specimen has a midline skull length of 189 millimetres, compared to 272 millimetres for ''Zanabazar junior'', itself e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Troodon
''Troodon'' ( ; ''Troödon'' in older sources) is a wastebasket taxon and a dubious genus of relatively small, bird-like dinosaurs known definitively from the Campanian age of the Late Cretaceous period (about 77 mya). It includes at least one species, ''Troodon formosus'', known from Montana. Discovered in October 1855, ''T. formosus'' was among the first dinosaurs found in North America, although it was thought to be a lizard until 1877. Several well-known troodontid specimens from the Dinosaur Park Formation in Alberta were once believed to be members of this genus. However, recent analyses in 2017 have found the genus to be undiagnostic and referred some of these specimens to the genus ''Stenonychosaurus'' (long believed to be synonymous with ''Troodon'') and others to the genus ''Latenivenatrix''. The genus name is Ancient Greek for "wounding tooth", referring to the teeth, which were different from those of most other theropods known at the time of their discovery. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plesiomorphic
In phylogenetics, a plesiomorphy ("near form") and symplesiomorphy are synonyms for an ancestral character shared by all members of a clade, which does not distinguish the clade from other clades. Plesiomorphy, symplesiomorphy, apomorphy, and synapomorphy, all mean a trait shared between species because they share an ancestral species. Apomorphic and synapomorphic characteristics convey much information about evolutionary clades and can be used to define taxa. However, plesiomorphic and symplesiomorphic characteristics cannot. The term ''symplesiomorphy'' was introduced in 1950 by German entomologist Willi Hennig. Examples A backbone is a plesiomorphic trait shared by birds and mammals, and does not help in placing an animal in one or the other of these two clades. Birds and mammals share this trait because both clades are descended from the same far distant ancestor. Other clades, e.g. snakes, lizards, turtles, fish, frogs, all have backbones and none are either birds no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mei (dinosaur)
''Mei'' (from Chinese 寐 mèi ''Sleepy'') is a genus of duck-sized troodontid dinosaur first unearthed by paleontologists from the Yixian Formation in Liaoning, China in 2004. ''Mei'' lived during the Early Cretaceous period. The binomial name of its only species, ''Mei long'' (Chinese 寐 mèi and 龍 lóng), means ''sleeping dragon''. Description ''Mei'' is a troodontid, a group of small, bird-like, gracile maniraptorans. All troodontids have many unique features of the skull, such as closely spaced teeth in the lower jaw, and large numbers of teeth. Troodontids have sickle-claws and raptorial hands, and some of the highest non-avian encephalization quotients, meaning they were behaviourally advanced and had keen senses. The type fossil is a young juvenile about long, complete and exceptionally well preserved in three-dimensional detail, with the snout nestled beneath one of the forelimbs and the legs neatly folded beneath the body, similar to the roosting position of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
