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Pygostylian
Pygostylia is a group of avialans which includes the Confuciusornithidae and all of the more advanced species, the Ornithothoraces. Definition The group Pygostylia was intended to encompass all avialans with a short, stubby tail, as opposed to the longer, unfused tails of more primitive species like ''Archaeopteryx lithographica''. It was named by Sankar Chatterjee in 1997.Chatterjee, S. 1997. ''The Rise of Birds.'' Baltimore: Johns Hopkins University Press. 312 pp. Luis Chiappe later defined Pygostylia as a node-based clade, "the common ancestor of the Confuciusornithidae and Neornithes plus all its descendants". In 2001, Jacques Gauthier and Kevin de Queiroz recommended that Chatterjee's original apomorphy-based clade concept be used instead of Chiappe's node-based definition,Gauthier, J., & De Queiroz, K. (2001). Feathered dinosaurs, flying dinosaurs, crown dinosaurs, and the name" Aves. ''New perspectives on the origin and early evolution of birds'', 7-41. but this recommenda ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jinguofortisidae
Jinguofortisidae is an extinct family of early pygostylian avialans known from the Early Cretaceous, found in northern China. Description The Jinguofortisidae are distinguished from other non-ornithothoracine avialans by the following features: the scapula and coracoid fused into a scapulocoracoid; a boomeranged-shaped furcula without a hypocleidium; proximal margin of humerus concave centrally; deltopectoral crest large and not perforated; minor metacarpal markedly bowed caudally; alular digit terminating at the level of the distal end of major metacarpal; and proximal phalanx of the major digit longer than the intermediate phalanx. Phylogeny Wang et al. (2018) erected Jinguofortisidae after finding ''Chongmingia'' (previously considered Avebrevicauda ''incertae sedis'' by Wang et al. 2016) to be sister to their new taxon ''Jinguofortis''. In 2023, a third jinguofortisid was described by Li ''et al''. They recovered their new taxon, ''Cratonavis'', as the sister taxon to ''Ch ... [...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] |
Confuciusornithiformes
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 digestiv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protopteryx Fengningensis
''Protopteryx'' is an extinct bird and the most basal enantiornithean, from the Cretaceous period.Zhou, Zhonghe. (2002). "A new and primitive enantiornithine bird from the Early Cretaceous of China." ''Journal of Vertebrate Paleontology'', 22(1): 49-57. The type species is ''P. fengningensis''. It was first discovered in the Sichakou Member of the Yixian Formation or Huajiying Formation of Hebei Province, northern China, dating from 131 Ma ago.O'Connor, J.K., Zhou Z. and Zhang F. (In press). "A reappraisal of ''Boluochia zhengi'' (Aves: Enantiornithes) and a discussion of intraclade diversity in the Jehol avifauna, China." ''Journal of Systematic Palaeontology'', (published online before print 16 December 2010). ''Protopteryx ''has been found in the Daibeigou formation, as well.Zhiheng Li, Zhonghe Zhou, Min Wang, Julia A. Clarke, (2014). "A New Specimen of Large-Bodied Basal Enantiornithine ''Bohaiornis'' from the Early Cretaceous of China and the Inference of Feeding Ecology i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ploughshare
In agriculture, a plowshare ( US) or ploughshare ( UK; ) is a component of a plow (or plough). It is the cutting or leading edge of a moldboard which closely follows the coulter (one or more ground-breaking spikes) when plowing. The plowshare itself is often a hardened blade dressed into an integral moldboard (by the blacksmith) so making a unified combination of plowshare and moldboard, the whole being responsible for entering the cleft in the earth (made by the coulter's first cutting-through) and turning the earth over. In well-tilled terrain the plowshare may do duty without a preceding coulter. In modern plows both coulter and plowshare are detachable for easy replacement when worn or broken. History Triangular-shaped stone ploughshares are found at the sites of Chinese Majiabang culture dated to 3500 BC around Lake Tai. Ploughshares have also been discovered at the nearby Liangzhu and Maqiao sites roughly dated to the same period. The British archaeologist David R. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tibiotarsus
The tibiotarsus is the large bone between the femur and the tarsometatarsus in the leg of a bird. It is the fusion of the proximal part of the tarsus with the tibia. A similar structure also occurred in the Mesozoic Heterodontosauridae. These small ornithischian dinosaurs were unrelated to birds and the similarity of their foot bones is best explained by convergent evolution. See also * Bird anatomy References * Proctor, Nobel S. ''Manual of Ornithology: Avian Structure and Function''. Yale University Press Yale University Press is the university press of Yale University. It was founded in 1908 by George Parmly Day, and became an official department of Yale University in 1961, but it remains financially and operationally autonomous. , Yale Univer .... (1993) Bird anatomy {{ornithology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Condyle (anatomy)
A condyle (; in Merriam-Webster Online Dictionary '. la, condylus, from el, kondylos; κόνδυλος knuckle) is the round prominence at the end of a , most often part of a joint – an articulation with another bone. It is one of the markings or features of bones, and can refer to: * On the , in the |
Anatomical Terms Of Location
Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position provides a definition of what is at the front ("anterior"), behind ("posterior") and so on. As part of defining and describing terms, the body is described through the use of anatomical planes and anatomical axes. The meaning of terms that are used can change depending on whether an organism is bipedal or quadrupedal. Additionally, for some animals such as invertebrates, some terms may not have any meaning at all; for example, an animal that is radially symmetrical will have no anterior surface, but can still have a description that a part is close to the middle ("proximal") or further from the middle ("distal"). International organisations have determined vocabularies that are often used as standard vocabularies for subdisciplines o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sacrum
The sacrum (plural: ''sacra'' or ''sacrums''), in human anatomy, is a large, triangular bone at the base of the spine that forms by the fusing of the sacral vertebrae (S1S5) between ages 18 and 30. The sacrum situates at the upper, back part of the pelvic cavity, between the two wings of the pelvis. It forms joints with four other bones. The two projections at the sides of the sacrum are called the alae (wings), and articulate with the ilium at the L-shaped sacroiliac joints. The upper part of the sacrum connects with the last lumbar vertebra (L5), and its lower part with the coccyx (tailbone) via the sacral and coccygeal cornua. The sacrum has three different surfaces which are shaped to accommodate surrounding pelvic structures. Overall it is concave (curved upon itself). The base of the sacrum, the broadest and uppermost part, is tilted forward as the sacral promontory internally. The central part is curved outward toward the posterior, allowing greater room for the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pubis (bone)
In vertebrates, the pubic region ( la, pubis) is the most forward-facing (ventral and anterior) of the three main regions making up the coxal bone. The left and right pubic regions are each made up of three sections, a superior ramus, inferior ramus, and a body. Structure The pubic region is made up of a ''body'', ''superior ramus'', and ''inferior ramus'' (). The left and right coxal bones join at the pubic symphysis. It is covered by a layer of fat, which is covered by the mons pubis. The pubis is the lower limit of the suprapubic region. In the female, the pubic region is anterior to the urethral sponge. Body The body forms the wide, strong, middle and flat part of the pubic region. The bodies of the left and right pubic regions join at the pubic symphysis. The rough upper edge is the pubic crest, ending laterally in the pubic tubercle. This tubercle, found roughly 3 cm from the pubic symphysis, is a distinctive feature on the lower part of the abdominal wall; important ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypantrum
The hyposphene-hypantrum articulation is an accessory joint found in the vertebrae of several fossil reptiles of the group Archosauromorpha. It consists of a process on the backside of the vertebrae, the hyposphene, that fits in a depression in the front side of the next vertebrae, the hypantrum. Hyposphene-hypantrum articulations occur in the dorsal vertebrae and sometimes also in the posteriormost cervical and anteriormost caudal vertebrae. In most tetrapods including the human, the vertebrae are connected with each other only via the centrum and the zygapophysis joints. Additional joints like the hyposphene-hypantrum articulations, which add rigidity to the vertebral column, are found in several different reptile lineages; a known example are the zygosphene-zygantrum articulations found in snakes. Hyposphene-hypantrum articulations are found in several unrelated groups within the Archosauromorpha. They occur especially in large forms, for example in rauisuchids and in silesaur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hyposphene
The hyposphene-hypantrum articulation is an accessory joint found in the vertebrae of several fossil reptiles of the group Archosauromorpha. It consists of a process on the backside of the vertebrae, the hyposphene, that fits in a depression in the front side of the next vertebrae, the hypantrum. Hyposphene-hypantrum articulations occur in the dorsal vertebrae and sometimes also in the posteriormost cervical and anteriormost caudal vertebrae. In most tetrapods including the human, the vertebrae are connected with each other only via the centrum and the zygapophysis joints. Additional joints like the hyposphene-hypantrum articulations, which add rigidity to the vertebral column, are found in several different reptile lineages; a known example are the zygosphene-zygantrum articulations found in snakes. Hyposphene-hypantrum articulations are found in several unrelated groups within the Archosauromorpha. They occur especially in large forms, for example in rauisuchids and in silesaur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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