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Ilek Formation
The Ilek Formation is a Lower Cretaceous geologic formation in Western Siberia. Many different fossils have been recovered from the formation. It overlies the Late Jurassic Tyazhin Formation and underlies the Albian Kiya Formation. The formation was described by L. A. Ragozin in 1935. It consists of sands with sandstone concretions, layers of silts, clays and marls. Age of the formation, according to a crude 1962 estimate, is Valanginian(?) - Hauterivian - Barremian. Its thickness varies greatly, reaching 746 m in Teguldet borehole. Fauna A fragmentary wing metatarsal nearly identical to the pterosaur ''Lonchognathosaurus'' is also known. See also * List of pterosaur-bearing stratigraphic units This is a list of stratigraphic units, where pterosaur fossils have been recovered from. Units listed are all either formation rank or higher (e.g. group). See also * Pterosaur * List of fossil sites References Further reading * Ext ... References {{Refli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geological Formation
A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics ( lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exposed in a geographical region (the stratigraphic column). It is the fundamental unit of lithostratigraphy, the study of strata or rock layers. A formation must be large enough that it can be mapped at the surface or traced in the subsurface. Formations are otherwise not defined by the thickness of their rock strata, which can vary widely. They are usually, but not universally, tabular in form. They may consist of a single lithology (rock type), or of alternating beds of two or more lithologies, or even a heterogeneous mixture of lithologies, so long as this distinguishes them from adjacent bodies of rock. The concept of a geologic formation goes back to the beginnings of modern scientific geology. The term was used by Abraham Gottlob Wer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hauterivian
The Hauterivian is, in the geologic timescale, an age in the Early Cretaceous Epoch or a stage in the Lower Cretaceous Series. It spans the time between 132.9 ± 2 Ma and 129.4 ± 1.5 Ma (million years ago). The Hauterivian is preceded by the Valanginian and succeeded by the Barremian.See Gradstein ''et al.'' (2004) for a detailed geologic timescale Stratigraphic definitions The Hauterivian was introduced in scientific literature by Swiss geologist Eugène Renevier in 1873. It is named after the Swiss town of Hauterive at the shore of Lake Neuchâtel. The base of the Hauterivian is defined as the place in the stratigraphic column where the ammonite genus ''Acanthodiscus'' first appears. A reference profile for the base (a GSSP) was officially ratified by the International Union of Geological Sciences in December of 2019, and is placed in La Charce, France. The top of the Hauterivian (the base of the Barremian) is at the first appearance of ammonite species ''Spitidiscus hugii'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Psittacosaurus Sibiricus
''Psittacosaurus'' ( ; "parrot lizard") is a genus of extinct ceratopsian dinosaur from the Early Cretaceous of what is now Asia, existing between 126 and 101 million years ago. It is notable for being the most species-rich non-avian dinosaur genus. Up to 12 species are known, from across China, Mongolia, Russia, and Thailand. The species of ''Psittacosaurus'' were obligate bipeds at adulthood, with a high skull and a robust beak. One individual was found preserved with long filaments on the tail, similar to those of ''Tianyulong''. ''Psittacosaurus'' probably had complex behaviours, based on the proportions and relative size of the brain. It may have been active for short periods of time during the day and night, and had well-developed senses of smell and vision. ''Psittacosaurus'' was one of the earliest ceratopsians, but closer to ''Triceratops'' than ''Yinlong''. Once in its own family, Psittacosauridae, with other genera like ''Hongshanosaurus'', it is now considered to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ceratopsia
Ceratopsia or Ceratopia ( or ; Greek: "horned faces") is a group of herbivorous, beaked dinosaurs that thrived in what are now North America, Europe, and Asia, during the Cretaceous Period, although ancestral forms lived earlier, in the Jurassic. The earliest known ceratopsian, ''Yinlong downsi'', lived between 161.2 and 155.7 million years ago.Holtz, Thomas R. Jr. (2011) ''Dinosaurs: The Most Complete, Up-to-Date Encyclopedia for Dinosaur Lovers of All Ages,'Winter 2010 Appendix./ref> The last ceratopsian species, ''Triceratops prorsus'', became extinct during the Cretaceous–Paleogene extinction event, . ''Triceratops'' is by far the best-known ceratopsian to the general public. It is traditional for ceratopsian genus names to end in "''-ceratops''", although this is not always the case. One of the first named genera was ''Ceratops'' itself, which lent its name to the group, although it is considered a '' nomen dubium'' today as its fossil remains have no distinguishing charact ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Psittacosaurus
''Psittacosaurus'' ( ; "parrot lizard") is a genus of extinct ceratopsian dinosaur from the Early Cretaceous of what is now Asia, existing between 126 and 101 million years ago. It is notable for being the most species-rich non-avian dinosaur genus. Up to 12 species are known, from across China, Mongolia, Russia, and Thailand. The species of ''Psittacosaurus'' were obligate bipeds at adulthood, with a high skull and a robust beak. One individual was found preserved with long filaments on the tail, similar to those of ''Tianyulong''. ''Psittacosaurus'' probably had complex behaviours, based on the proportions and relative size of the brain. It may have been active for short periods of time during the day and night, and had well-developed senses of smell and vision. ''Psittacosaurus'' was one of the earliest ceratopsians, but closer to ''Triceratops'' than ''Yinlong''. Once in its own family, Psittacosauridae, with other genera like ''Hongshanosaurus'', it is now considered to be s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enantiornithean
The Enantiornithes, also known as enantiornithines or enantiornitheans in literature, are a group of extinct avialans ("birds" in the broad sense), the most abundant and diverse group known from the Mesozoic era. Almost all retained teeth and clawed fingers on each wing, but otherwise looked much like modern birds externally. Over eighty species of Enantiornithes have been named, but some names represent only single bones, so it is likely that not all are valid. The Enantiornithes became extinct at the Cretaceous–Paleogene boundary, along with Hesperornithes and all other non-avian dinosaurs. Discovery and naming The first Enantiornithes to be discovered were incorrectly referred to modern bird groups. For example, the first known species of Enantiornithes, '' Gobipteryx minuta'', was originally considered a paleognath related to ostriches and tinamou. The Enantiornithes were first recognized as a distinct lineage, or "subclass" of birds, by Cyril A. Walker in 1981. Walker mad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Avisaurid
Avisauridae is a family of extinct enantiornithine dinosaurs from the Cretaceous period, distinguished by several features of their ankle bones. Depending on the definition used, Avisauridae is either a broad and widespread group of advanced enantiornithines (following Cau & Arduini, 2008), or a small family within that group, restricted to species from the Late Cretaceous of North and South America (following Chiappe, 1992). Description Avisaurids were among the largest and last enantiornithines to have lived, although they are also among the most poorly preserved. The majority of them are known primarily from fossilized tarsometatarsal bones, the part of a bird's leg formed by fused metatarsals (the bones which comprise the foot in humans). As a result, members of this family are distinguished from other enantiornithines exclusively by features of the tarsometatarsal and pedal phalanges (toe bones). Unlike in some prehistoric birds, avisaurid tarsometatarsals were not comple ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Western Siberia
Western Siberia or West Siberia (russian: Западная Сибирь, Zapadnaya Sibir'; kk, Батыс Сібір) is a part of the larger region of Siberia that is mostly located in the Russian Federation. It lies between the Ural region and the Yenisei River, which conventionally divides Siberia into two halves. Western Siberia covers an area of , nearly 80% of which is located within the West Siberian Plain. The largest rivers of the region are the Irtysh and the Ob. The West Siberian petroleum basin is the largest hydrocarbon (petroleum and natural gas) basin in the world covering an area of about 2.2 million km2, and is also the largest oil and gas producing region in Russia. In medieval times, the region was part of the Golden Horde. After its gradual decline during the 15th century, the Khanate of Sibir, centered on Tyumen, was formed within the area. In the late 16th century, most of Western Siberia was conquered by the Russian Empire, while its southern region be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mystiornis
''Mystiornis'' is an extinct genus of bird which existed in what is now western Siberia, Russia during the early Cretaceous period (Barremian/ Aptian age). It is known from an isolated metatarsus found in the Shestakovo-1 locality of southern Western Siberia. It was named by Evgeny N. Kurochkin, Nikita V. Zelenkov, Alexandr O. Averianov and Sergei V. Leshchinskiy in 2011, and the type species is ''Mystiornis cyrili''. While most recent studies place it as an Enantiornithine, specifically an Avisaurid, the authors note that the placement in both groups is tentative and further material will be required to make a firm decision on placement due to the unusual features of the existing material. Based on the strongly shortened metatarsal II and orientation of throchleae, ''Mystiornis'' had diving adaptations similar to that of ''Gansus'' and ''Neogaeornis ''Neogaeornis'' is a controversial prehistoric genus of diving bird. The single known species, ''Neogaeornis wetzeli'', was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Evgenavis Tarsometatarsus
''Evgenavis'' (named after the Russian paleontologist Evgeny Kurochkin) is a genus of extinct basal bird that lived from the Barremian to the Aptian. The type specimen ZIN PH 1/154 is an isolated tarsometatarsus found in the Ilek Formation (Shestakovo locality), Western Siberia. ''Evgenavis'' may have been the only confuciusornithiform known outside the Jehol Biota, although there is also the possibility that it could have been a different type of avialan, such as an enantiornithean or a relative of ''Vorona''. A cladogram A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to d ... within a 2019 study involving a wide range of theropods included ''Evgenavis'' as a longipterygid.Hartman, Scott; Mortimer, Mickey; Wahl, William R.; Lomax, Dean R.; Lippincott, Jessica; Lovelace, David M. (201 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Confuciusornithiform
Confuciusornithidae is an extinct family of pygostylian avialans known from the Early Cretaceous, found in northern China. They are commonly placed as a sister group to Ornithothoraces, a group that contains all extant birds along with their closest extinct relatives. Confuciusornithidae contains four genera, possessing both shafted and non-shafted (downy) feathers. They are also noted for their distinctive pair of ribbon-like tail feathers of disputed function. The wing anatomy of confuciusornithids suggests an unusual flight behavior, due to anatomy that implies conflicting abilities. They possessed feathers similar to those of fast-flapping birds, which rely on quick flapping of their wings to stay aloft. At the same time, their wing anatomy also suggests a lack of flapping ability. Confuciusornithids are also noted for their beak and lack of teeth, similar to modern birds. Both predators and prey, confuciusornithid fossils have been observed with fish remains in their digestive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Evgenavis
''Evgenavis'' (named after the Russian paleontologist Evgeny Kurochkin) is a genus of extinct basal bird that lived from the Barremian to the Aptian. The type specimen ZIN PH 1/154 is an isolated tarsometatarsus found in the Ilek Formation (Shestakovo locality), Western Siberia. ''Evgenavis'' may have been the only confuciusornithiform known outside the Jehol Biota, although there is also the possibility that it could have been a different type of avialan, such as an enantiornithean or a relative of ''Vorona''. A cladogram A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to d ... within a 2019 study involving a wide range of theropods included ''Evgenavis'' as a longipterygid.Hartman, Scott; Mortimer, Mickey; Wahl, William R.; Lomax, Dean R.; Lippincott, Jessica; Lovelace, David M. (201 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
