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Alvarezsaurids
Alvarezsauridae is a family of small, long-legged dinosaurs. Although originally thought to represent the earliest known flightless birds, they are now thought to be an early diverging branch of maniraptoran theropods. Alvarezsaurids were highly specialized. They had tiny but stout forelimbs, with compact, bird-like hands. Their skeletons suggest that they had massive breast and arm muscles, possibly adapted for digging or tearing. They had long, tube-shaped snouts filled with tiny teeth. They have been interpreted as myrmecophagous, adapted to prey on colonial insects such as termites, with the short arms acting as effective digging instruments to break into nests. '' Alvarezsaurus'', the type genus of the family, was named for the historian Gregorio Álvarez. History of study Bonaparte (1991) described the first alvarezsaurid, '' Alvarezsaurus calvoi'', from an incomplete skeleton found in Patagonia, Argentina. Bonaparte also named a family, Alvarezsauridae, to contain it. H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shuvuuia
''Shuvuuia'' is a genus of bird-like theropod dinosaur from the late Cretaceous period of Mongolia. It is a member of the family Alvarezsauridae, small coelurosaurian dinosaurs which are characterized by short but powerful forelimbs specialized for digging. The type (and only known) species is ''Shuvuuia deserti'', or "desert bird". The name ''Shuvuuia'' is derived from the Mongolian word ''shuvuu'' (шувуу) meaning "bird". Description ''Shuvuuia'' was a small and lightly built animal. At in length and in body mass, it is one of the smallest known non-avian dinosaurs. The skull is lightly built with long and slender jaws and minute teeth. ''Shuvuuia'' is unique among non-avian theropods in the skull's ability to perform prokinesis; that is, it could flex its upper jaw independently of its braincase. The hindlimbs of ''Shuvuuia'' were long, slender, and short-toed, which may indicate significant running capabilities. The forelimbs, however, were unusually short and power ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bonapartenykus
''Bonapartenykus'' (meaning "José Bonaparte, José F. Bonaparte's claw") is a monospecific genus of alvarezsauroidea, alvarezsauroid dinosaur from Argentina that lived during the Late Cretaceous (Campanian-Maastrichtian) in what is now the upper Allen Formation of the Río Negro Province. The type and only species, ''Bonapartenykus ultimus'', is known from a nearly articulated but partial skeleton that was found in close association to two incomplete egg, eggs and several clusters of eggshells belonging to the egg fossils, oogenus ''Arriagadoolithus''. ''Bonapartenykus'' was named in 2012 in paleontology, 2012. It has an estimated length of and weight of , making it the largest member of the clade Alvarezsauroidea. Discovery and naming A partial skeleton of a theropod with eggs was collected in a surface of approximately 30 m2 in fluvial processes, fluvial sandstone, sandstones of the upper Allen Formation in northwestern Patagonia, Argentina. The locality has also produced s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xixianykus
''Xixianykus'' is a genus of alvarezsaurid theropod dinosaur from the late Cretaceous period of China. Known from a slab of rock which contains a partial postcranial skeleton unearthed in the Late Cretaceous ( Coniacian-Santonian) Majiacun Formation of the Xixia Basin in Henan, China. Discovery and naming The fossil, holotype XMDFEC V0011, was found in the Majiacun Formation in Henan Province, China. The fossil consists of a partial skeleton, without the skull. Parts of the hind legs, pelvis and spine has also been recovered. ''Xixianykus'' is among the oldest of the derived alvarezsauroids, the parvicursorines, dated to the Santonian– Coniacian, as opposed to other parvicursorines, which are either Campanian or Maastrichtian.Hone, D. (2010)''Xixianykus zhangi'' - A New AlvarezsaurDave Hone's Archosaur Musings, April 23, 2011. The type species is ''Xixianykus zhangi'' described in 2010 by Xu Xing. The genus name refers to Xixia County and to the Greek word for claw ("''o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ceratonykus
''Ceratonykus'' (meaning "horned claw") is a monospecific genus of alvarezsaurid dinosaur from Mongolia that lived during the Late Cretaceous (late Campanian stage, 72.1 Ma) in what is now the Barun Goyot Formation. The type and only species, ''Ceratonykus oculatus'', is known from a fragmentary skeleton, including an incomplete skull, of an adult individual. It was named and described in 2009 by Vladimir Alifanov and Rinchen Barsbold. Its describers questioned the traditional placement of alvarezsaurs in Theropoda, instead suggesting they were ornithischians, but this has not been accepted since. ''Ceratonykus'' has an estimated length of and weight of . It has been considered as a possible junior synonym of '' Parvicursor''. Discovery and naming In 2003, a partial skeleton of an alvarezsaurid was discovered in the Barun Goyot Formation of the Khermiin Tsav locality, Mongolia by the Paleontological Center of the Mongolian Academy of Sciences (MPC) preparator Otkhoon Zhargal. ... [...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] |
Parvicursor
''Parvicursor'' (meaning "small runner") is a genus of tiny maniraptoran dinosaur with long slender legs for fast running. Discovery and naming The holotype PIN no. 4487/25, mostly consisting of vertebrae, the pelvis and the right hindlimb, was discovered in 1992 and described in 1996.Karhu, A.A. and Rautian, A.S. (1996). "A new family of Maniraptora (Dinosauria: Saurischia) from the Late Cretaceous of Mongolia". ''Paleontological Journal'' ''Russian Academy of Sciences'' 30(5): 583-592. It was discovered in Barun Goyot Formation of Khulsan, Mongolia, dated at approximately 72 million years old. Description At only about from snout to end of tail, and in weight, it was initially seen as one of the smallest non-avian dinosaurs known from an adult specimen.Which was the smallest dinosaur? Royal Tyrrell Mu ... [...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 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] |
Family (biology)
Family (, : ) is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between order and genus. A family may be divided into subfamilies, which are intermediate ranks between the ranks of family and genus. The official family names are Latin in origin; however, popular names are often used: for example, walnut trees and hickory trees belong to the family Juglandaceae, but that family is commonly referred to as the "walnut family". The delineation of what constitutes a family—or whether a described family should be acknowledged—is established and decided upon by active taxonomists. There are not strict regulations for outlining or acknowledging a family, yet in the realm of plants, these classifications often rely on both the vegetative and reproductive characteristics of plant species. Taxonomists frequently hold varying perspectives on these descriptions, leading to a lack of widespread consensus within the scientific community ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyril Walker (ornithologist)
Cyril Alexander Walker (8 February 1939 – 6 May 2009) was a British palaeontologist, curator of fossil birds in the Natural History Museum. He was also interested in fossil turtles. book, '' Smithsonian Handbook of Fossils''. He has also contributed to many other books, including ''Garden Birds'', ''Field Guide to British Birds'', ''Birds of the World'', ''Nature Notebooks'', and others. An unidentified moa bone of unknown origin and locality, donated by Dr. C. Walker to ornithologist Zlatozar Boev in 1986, was later identified as the little bush moa (''Anomalopteryx didiformis'').1. Boev, Z. 2018. A specimen of little bush moa Anomalopteryx didiformis (Owen, 1844), Emeidae Bonaparte, 1854 from the National Museum of Natural History, Sofia. – Historia naturalis bulgarica, 32: 3-5. It is the only specimen of Dinornithiformes in the collections of the National Museum of Natural History, Bulgarian Academy of Sciences in Sofia. References British palaeontologists Briti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Colin Harrison (ornithologist)
Colin James Oliver Harrison (18 August 1926 – 17 November 2003) was an English ornithologist. Harrison was born in London. He got a scholarship to grammar school, and then worked as a librarian and a teacher. He had been interested in birds since childhood, and joined an expedition to study autumn migration in Norway. He became a professional ornithologist at the age of 34 and became responsible for the care of the national collection of birds' nests and eggs in the Bird Room at the Natural History Museum at Tring, Hertfordshire. In 1966 he led the fourth of the series of Harold Hall Australian ornithological collecting expeditions. Harrison later became interested in biogeography Biogeography is the study of the species distribution, distribution of species and ecosystems in geography, geographic space and through evolutionary history of life, geological time. Organisms and biological community (ecology), communities o ... and the museum's avian paleontological collect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linhenykus
''Linhenykus'' is an extinct genus of alvarezsaurid theropod dinosaur from the Late Cretaceous of Inner Mongolia, China. It is the most basal known member of the Parvicursorinae. The genus gets its name from Linhe, a city near the site where the fossil was first found and Greek ''nykus'', "claw". The specific name is derived from Greek ''monos'', "single", and ''daktylos'', "finger", a reference to the fact that it is the only known non-avian dinosaur to have had but a single digit. Description ''Linhenykus'' was a small dinosaur, measuring long and weighing . Its femur length is . Alvarezsauroids are known for their short forelimbs, each with a single greatly enlarged second digit. Although alvarezsaurids were once thought to have only a single digit on each forelimb, more recent evidence has shown that most species have reduced third and fourth digits. ''Linhenykus'' is the first known alvarezsaurid to have only a single, second digit. Although a reduced third metacarpal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
