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Bullatosauria
Maniraptoriformes is a clade of dinosaurs with pennaceous feathers and wings that contains ornithomimosaurs and maniraptorans. This group was named by Thomas Holtz, who defined it as "the most recent common ancestor of '' Ornithomimus'' and birds, and all descendants of that common ancestor." Fossil evidence Many fossils have been discovered in recent years, particularly in China. Many of the feathered dinosaurs belong to this clade. In particular, a fossil of the Alvarezsauridae '' Shuvuuia'' has a version of keratin consistent with that of avian feathers. Many nearly complete fossil maniraptoriforms are known from the late Jurassic. ''Archaeopteryx'' is known from Bavaria at 155–150 Ma. '' Ornitholestes'', the troodontid ''Hesperornithoides'', '' Coelurus fragilis'' and '' Tanycolagreus topwilsoni'' are all known from the Morrison Formation in Wyoming at about 150 Ma. The Daohugou biota, including ''Anchiornis'' and ''Epidexipteryx'', is the earliest record of ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Middle Jurassic
The Middle Jurassic is the second Epoch (geology), epoch of the Jurassic Period (geology), Period. It lasted from about 174.1 to 163.5 million years ago. Fossils of land-dwelling animals, such as dinosaurs, from the Middle Jurassic are relatively rare, but geological formations containing land animal fossils include the Forest Marble Formation in England, the Kilmaluag Formation in Scotland,British Geological Survey. 2011Stratigraphic framework for the Middle Jurassic strata of Great Britain and the adjoining continental shelf: research report RR/11/06 British Geological Survey, Keyworth, Nottingham. the Daohugou Beds in China, the Itat Formation in Russia, and the Isalo III Formation of western Madagascar. Paleogeography During the Middle Jurassic Epoch, Pangaea began to separate into Laurasia and Gondwana, and the Atlantic Ocean formed. Eastern Laurasia was tectonically active as the Cimmerian plate continued to collide with Laurasia's southern coast, completely closing the Pale ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Fossil Birds
Birds evolved from certain feathered theropod dinosaurs, and there is no real dividing line between birds and non-avian dinosaurs except that some of the former survived the Cretaceous–Paleogene extinction event while the latter did not. For the purposes of this article, a 'bird' is considered to be any member of the clade Aves in the broadest sense.Sereno (2005) Some dinosaur groups which may or may not be true birds are listed below under Proto-birds. This page contains a listing of prehistoric bird taxa only known from completely fossilized specimens. These extinctions took place before the Late Quaternary and thus took place in the absence of significant human interference. While the earliest hominids had been eating birds and especially their eggs, human population and technology was simply insufficient to seriously affect healthy bird populations until the Upper Paleolithic Revolution. Rather, reasons for the extinctions listed here are stochastic abiotic events such as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epidexipteryx
''Epidexipteryx'' is a genus of small paravian dinosaurs, known from one fossil specimen in the collection of the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing. ''Epidexipteryx'' represents the earliest known example of ornamental feathers in the fossil record. Discovery The type specimen is catalog number IVPP V 15471. The specific name, ''Epidexipteryx hui'' ("Hu's display feather"), and its Chinese name ''Hushi Yaolong'' ("Hu Yaoming's dragon") were coined in memory of paleomammologist Hu Yaoming. Due to a pre-publication error,Dr. Thomas Holtz, Jr. "The mistaken scansoripterygid". Message to the Dinosaur Mailing List (October 1, 2008) a manuscript of the ''Epidexipteryx hui'' description first appeared on a preprint Web portal in late September 2008. The paper was officially published in the October 23, 2008 issue of the journal ''Nature''. Description ''E. hui'' is known from a well-preserved partial skeleton that includes four long feathers o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anchiornis
''Anchiornis'' is a genus of small, four-winged paravian dinosaurs, with only one known species, the type species ''Anchiornis huxleyi'', named for its similarity to modern birds. The Latin name ''Anchiornis'' derives from a Greek word meaning "near bird", and ''huxleyi'' refers to Thomas Henry Huxley, a contemporary of Charles Darwin. ''Anchiornis'' fossils have been found only in the Tiaojishan Formation of Liaoning, China, in rocks dated to the Late Jurassic, about 160 million years ago. It is known from hundreds of specimens, and given the exquisite preservation of some of these fossils, it became the first Mesozoic dinosaur species for which almost the entire life appearance could be determined, and an important source of information on the early evolution of birds. Description ''Anchiornis huxleyi'' was a small, bipedal theropod dinosaur with a triangular skull bearing several details in common with dromaeosaurids, troodontids, and primitive avialans. Like other early ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Daohugou Biota
The Tiaojishan Formation is a geological formation in Hebei and Liaoning, People's Republic of China, dating to the middle-late Jurassic period (Bathonian- Oxfordian stages). It is known for its exceptionally preserved fossils, including those of plants, insects and vertebrates. It is made up mainly of pyroclastic rock interspersed with basic volcanic and sedimentary rocks. Previously, the Tiaojishan Formation was grouped together with the underlying Haifanggou Formation (also known as the Jiulongshan Formation) as a single "Lanqi Formation." The Tiaojishan Formation forms a key part of the Yanliao Biota assemblage, alongside the Haifanggou Formation. Age Using Argon–argon dating, Wang and colleagues in 2005 dated part of the Tiaojishan Formation to about 160 million years ago, the beginning of the Oxfordian stage, the first stage of the Upper Jurassic epoch. In 2006, a study by Liu and colleagues used U-Pb zircon dating to conclude that the Tiaojishan Formation correlates ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Morrison Formation
The Morrison Formation is a distinctive sequence of Upper Jurassic sedimentary rock found in the western United States which has been the most fertile source of dinosaur fossils in North America. It is composed of mudstone, sandstone, siltstone, and limestone and is light gray, greenish gray, or red. Most of the fossils occur in the green siltstone beds and lower sandstones, relics of the rivers and floodplains of the Jurassic period. It is centered in Wyoming and Colorado, with outcrops in Montana, North Dakota, South Dakota, Nebraska, Kansas, the panhandles of Oklahoma and Texas, New Mexico, Arizona, Utah, and Idaho. Equivalent rocks under different names are found in Canada. It covers an area of 1.5 million square kilometers (600,000 square miles), although only a tiny fraction is exposed and accessible to geologists and paleontologists. Over 75% is still buried under the prairie to the east, and much of its western paleogeographic extent was eroded during exhum ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tanycolagreus
''Tanycolagreus'' is a genus of coelurosaurian theropod from the Late Jurassic of North America. Discovery and naming In 1995 Western Paleontological Laboratories, Inc. uncovered the partial skeleton of a small theropod at the Bone Cabin Quarry West locality, Albany County, Wyoming, from the Salt Wash Member of the Morrison Formation, dating to the Oxfordian-Tithonian. At first the find was considered to be a specimen of '' Coelurus'' but subsequent study indicated it represented a species new to science, that in 2001 was announced to be named ''Tanycolagreus topwilsoni''. It was actually named and described by Kenneth Carpenter, Clifford Miles and Karen Cloward in 2005. The etymology of the generic name ''Tanycolagreus'', suggested by Ben Creisler, is based upon the greater length of its forelimbs and hindlimbs compared to ''Coelurus''. It is derived from the Greek prefix τανυ~, ''tany''~: 'long, stretched out', κῶλον, ''kolon'': 'limb' and ἀγρεύς, ''agreus' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coelurus
''Coelurus'' ( ) is a genus of coelurosaurian dinosaur from the Late Jurassic period (mid-late Kimmeridgian faunal stage, 155–152 million years ago). The name means "hollow tail", referring to its hollow tail vertebrae ( Greek κοῖλος, ''koilos'' = hollow + οὐρά, ''oura'' = tail). Although its name is linked to one of the main divisions of theropods ( Coelurosauria), it has historically been poorly understood, and sometimes confused with its better-known contemporary '' Ornitholestes''. Like many dinosaurs studied in the early years of paleontology, it has had a confusing taxonomic history, with several species being named and later transferred to other genera or abandoned. Only one species is currently recognized as valid: the type species, ''C. fragilis'', described by Othniel Charles Marsh in 1879. It is known from one partial skeleton found in the Morrison Formation of Wyoming, United States. It was a small bipedal carnivore with elongate legs. De ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hesperornithoides
''Hesperornithoides'' (meaning "western bird form"; nicknamed "Lori") is a genus of troodontid theropod dinosaur that lived in North America during the Late Jurassic period. Discovery Although several Troodontid teeth were found, with the troodontid '' Koparion'' named in 1994, a well preserved skeleton wasn't found until in 2001, a field crew from the Tate Museum supervised by William Wahl unexpectedly discovered the type skeleton ''Hesperornithoides'' in Jimbo Quarry of the Morrison Formation, overlying the excavation site of ''Supersaurus vivianae'', near Douglas, Wyoming. The muddy sandstone layers of the Jimbo Quarry from which ''Hesperornithoides'' came from the middle Morrison Formation dating to the between the Oxfordian and Tithonian ages of the Upper Jurassic.Trujillo, K., Chamberlain, K., & Strickland, A. (2006). Oxfordian Park: U/Pb ages from SHRIMP analysis for the Upper Jurassic Morrison Formation of southeastern Wyoming with implications for biostratigraphic corre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ornitholestes
''Ornitholestes'' (meaning "bird robber") is a small theropod dinosaur of the late Jurassic (Brushy Basin Member of the Morrison Formation, middle Kimmeridgian age, about 154 million years agoTurner, C.E. and Peterson, F., (1999). "Biostratigraphy of dinosaurs in the Upper Jurassic Morrison Formation of the Western Interior, U.S.A." Pp. 77–114 in Gillette, D.D. (ed.), ''Vertebrate Paleontology in Utah''. Utah Geological Survey Miscellaneous Publication 99-1.) of Western Laurasia (the area that was to become North America). To date, ''Ornitholestes'' is known only from a single partial skeleton with a badly crushed skull found at the Bone Cabin Quarry near Medicine Bow, Wyoming, in 1900. It was described by Henry Fairfield Osborn in 1903. An incomplete hand was later attributed to ''Ornitholestes'', although it now appears to belong to '' Tanycolagreus''. The type (and only known) species is ''O. hermanni''. The specific name honors the American Museum of Natural History p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archaeopteryx
''Archaeopteryx'' (; ), sometimes referred to by its German name, "" ( ''Primeval Bird''), is a genus of bird-like dinosaurs. The name derives from the ancient Greek (''archaīos''), meaning "ancient", and (''ptéryx''), meaning "feather" or "wing". Between the late 19th century and the early 21st century, ''Archaeopteryx'' was generally accepted by palaeontologists and popular reference books as the oldest known bird (member of the group Avialae). Older potential avialans have since been identified, including '' Anchiornis'', ''Xiaotingia'', and '' Aurornis''. ''Archaeopteryx'' lived in the Late Jurassic around 150 million years ago, in what is now southern Germany, during a time when Europe was an archipelago of islands in a shallow warm tropical sea, much closer to the equator than it is now. Similar in size to a Eurasian magpie, with the largest individuals possibly attaining the size of a raven, the largest species of ''Archaeopteryx'' could grow to about ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fossil
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in amber, hair, petrified wood and DNA remnants. The totality of fossils is known as the ''fossil record''. Paleontology is the study of fossils: their age, method of formation, and evolutionary significance. Specimens are usually considered to be fossils if they are over 10,000 years old. The oldest fossils are around 3.48 billion years old to 4.1 billion years old. Early edition, published online before print. The observation in the 19th century that certain fossils were associated with certain rock strata led to the recognition of a geological timescale and the relative ages of different fossils. The development of radiometric dating techniques in the early 20th century allowed scientists to quantitatively measure the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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