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2018 In Archosaur Paleontology
The year 2018 in archosaur paleontology was eventful. Archosaurs include the only living dinosaur group — birds — and the reptile crocodilians, plus all extinct dinosaurs, extinct crocodilian relatives, and pterosaurs. Archosaur palaeontology is the scientific study of those animals, especially as they existed before the Holocene Epoch began about 11,700 years ago. The year 2018 in paleontology included various significant developments regarding archosaurs. This article records new taxa of fossil archosaurs of every kind that have been described during the year 2018, as well as other significant discoveries and events related to paleontology of archosaurs that occurred in the year 2018. General research * A study on the morphology of dorsal vertebrae of extant and fossil archosaurs, and on its implications for inferring lung structure in non-avian dinosauriform archosaurs, is published by Brocklehurst, Schachner & Sellers (2018). * A study on the hip joint mobility of the ext ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archosaurs
Archosauria () is a clade of diapsids, with birds and crocodilians as the only living representatives. Archosaurs are broadly classified as reptiles, in the cladistic sense of the term which includes birds. Extinct archosaurs include non-avian dinosaurs, pterosaurs, and extinct relatives of crocodilians. Modern paleontologists define Archosauria as a crown group that includes the most recent common ancestor of living birds and crocodilians, and all of its descendants. The base of Archosauria splits into two clades: Pseudosuchia, which includes crocodilians and their extinct relatives, and Avemetatarsalia, which includes birds and their extinct relatives (such as non-avian dinosaurs and pterosaurs). Older definitions of the group Archosauria rely on shared morphological characteristics, such as an antorbital fenestra in the skull, serrated teeth, and an upright stance. Some extinct reptiles, such as proterosuchids and euparkeriids, possessed these features yet originate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kevin Padian
Kevin Padian (born 1951) is a Professor of Integrative Biology at the University of California, Berkeley, Curator of Paleontology, University of California Museum of Paleontology and was President of the National Center for Science Education from 2007 to 2008. Padian's area of interest is in vertebrate evolution, especially the origins of flight and the evolution of birds from theropod dinosaurs. He served as an expert witness for the plaintiffs in the ''Kitzmiller v. Dover Area School District'' trial, and his testimony was repeatedly cited in the court's decision. Padian received a bachelor's degree in Natural Science and a Master of Arts degree in Teaching from Colgate University, and a Ph.D. from Yale University, where he focused on the evolution of flight in pterosaurs. He subsequently became interested in paleobiology, especially using paleohistology. He developed this research program in collaboration with Armand de Ricqlès and Jack Horner. In addition to his work at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microraptor
''Microraptor'' (Greek, μικρός, ''mīkros'': "small"; Latin, ''raptor'': "one who seizes") is a genus of small, four-winged dromaeosaurid dinosaurs. Numerous well-preserved fossil specimens have been recovered from Liaoning, China. They date from the early Cretaceous Jiufotang Formation (Aptian stage), 125 to 120 million years ago. Three species have been named (''M. zhaoianus'', ''M. gui'', and ''M. hanqingi''), though further study has suggested that all of them represent variation in a single species, which is properly called ''M. zhaoianus''. ''Cryptovolans'', initially described as another four-winged dinosaur, is usually considered to be a synonym of ''Microraptor''. Like ''Archaeopteryx'', well-preserved fossils of ''Microraptor'' provide important evidence about the evolutionary relationship between birds and earlier dinosaurs. ''Microraptor'' had long pennaceous feathers that formed aerodynamic surfaces on the arms and tail but also on the legs. This led paleon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sinornithosaurus
''Sinornithosaurus'' (derived from a combination of Latin and Greek, meaning 'Chinese bird-lizard') is a genus of feathered dromaeosaurid dinosaur from the early Cretaceous Period (late Barremian) of the Yixian Formation in what is now China. It was the fifth non–avian feathered dinosaur genus discovered by 1999. The original specimen was collected from the Sihetun locality of western Liaoning. It was found in the Jianshangou beds of the Yixian Formation, dated to 124.5 million years ago. Additional specimens have been found in the younger Dawangzhangzi bed, dating to around 122 million years ago. Xu Xing described ''Sinornithosaurus'' and performed a phylogenetic analysis which demonstrated that it is basal, or primitive, among the dromaeosaurs. He has also demonstrated that features of the skull and shoulder are very similar to ''Archaeopteryx'' and other Avialae. Together these two facts demonstrate that the earliest dromaeosaurs were more like birds than the later dromaeosa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beipiaosaurus
''Beipiaosaurus'' is a genus of therizinosauroid theropod dinosaurs that lived in Asia during the Early Cretaceous in the Yixian Formation. The first remains were found in 1996 and formally described in 1999. Before the discovery of ''Yutyrannus'', they were among the heaviest dinosaurs known from direct evidence to be feathered. ''Beipiaosaurus'' is known from three reported specimens preserving numerous impressions of feather structures that allowed to determine the feathering color which turned out to be brownish. They were relatively small-sized therizinosaurs, measuring long and weighing about in contrast to the advanced and giant ''Segnosaurus'' or ''Therizinosaurus''. The necks of ''Beipiaosaurus'' were shorter than in most therizinosaurs, whose are characterized by elongated necks adapted for high-browsing. Also, their feet configuration differs from therizinosaurids, having a generic three-toed pes instead of four as seen in other members. The exact classification of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jeholornis
''Jeholornis'' (meaning "Jehol bird") is a genus of avialans that lived between approximately 122 and 120 million years ago during the early Cretaceous Period in China. Fossil ''Jeholornis'' were first discovered in the Jiufotang Formation in Hebei Province, China (in what was previously Rehe Province, also known as Jehol—hence the name) and additional specimens have been found in the older Yixian Formation. ''Jeholornis'' had long tails and few small teeth, and were approximately the size of turkeys,Holtz, Thomas R. Jr. (2008) ''Dinosaurs: The Most Complete, Up-to-Date Encyclopedia for Dinosaur Lovers of All Ages'Supplementary Information/ref> making them among the largest avialans known until the Late Cretaceous. Their diet included seeds of cycads, ''Ginkgo'' or similar plants. Description ''Jeholornis'' were relatively large, basal avialans, with a maximum adult length of up to 75 cm (2.5 ft) and an estimated weight of 2.27-9.1 kg (5-20 lbs). Another ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serikornis
''Serikornis'' is a genus of small, feathered anchiornithid dinosaur from the Upper Jurassic Tiaojishan Formation of Liaoning, China. It is represented by the type species ''Serikornis sungei''. Discovery ''Serikornis'', first described in August 2017, is noteworthy for the variety of feather types represented in its holotype, a single complete articulated skeleton preserved on a slab along with extensive integumentary structures. The specimen's feather imprints include wispy bundles along the neck, short and symmetrical vaned feathers on the arms, and both fuzz and long pennaceous feathers on its hindlimbs. While its anatomy and integument share features with birds as well as derived dromaeosaurs such as ''Microraptor'', cladistic analysis places the genus within the cluster of feathered dinosaurs near the origin of avians. It was unlikely to be a flier. Its name means "Ge Sun's silk bird", a reference to the plumulaceous-like body covering evident in the fossil. The specime ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eosinopteryx
''Eosinopteryx'' is an extinct genus of theropod dinosaurs known to the late Jurassic period of China. It contains a single species, ''Eosinopteryx brevipenna''. Discovery and naming ''E. brevipenna'' is known from a single fossil specimen recovered from the Tiaojishan Formation of western Liaoning Province, China, which has been dated to the late Jurassic period ( Oxfordian age), about 160 million years ago. The name ''Eosinopteryx'' is derived from the Greek ''eos'' ("daybreak" or "dawn"), the Latin ''Sinae'' ("Chinese"), and the Greek ''pteryx'' ("feather"). The specific name ''brevipenna'' (from the Latin ''brevis'', "short", and ''penna'', "feather") refers to the reduced plumage preserved in the type specimen, YFGP-T5197. Description ''Eosinopteryx brevipenna'' is known from a single fossil specimen representing the nearly complete skeleton of a subadult or adult individual. The specimen is very small for a non-avialan dinosaur, measuring about long. Unlike most troodonti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aurornis
''Aurornis'' is an extinct genus of anchiornithid theropod dinosaurs from the Jurassic period of China. The genus ''Aurornis'' contains a single known species, ''Aurornis xui'' (). ''Aurornis xui'' may be the most basal ("primitive") avialan dinosaur known to date, and it is one of the earliest avialans found to date. The fossil evidence for the animal pre-dates that of ''Archaeopteryx lithographica'', often considered the earliest bird species, by about 10 million years. ''Aurornis xui'' was first described and named by Pascal Godefroit, Andrea Cau, Hu Dong-Yu, François Escuillié, Wu Wenhao and Gareth Dyke in 2013. The generic name is derived from the Latin word ''aurora'', meaning "daybreak" or "dawn", and the Ancient Greek ὄρνις (''órnis'') meaning "bird". The specific name, ''A. xui'', honors Xu Xing. A recent study of specimens of the avialan ''Anchiornis'' has found that the traits exhibited by ''Aurornis'' fall within the range of variation in ''Anchiornis'', ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anchiornis
''Anchiornis'' is a genus of small, four-winged Paraves, 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 Province, 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, Bipedalism, bipedal Theropoda, theropod dinosaur with a triangular skull bearing several details in common with Dromaeosauridae, drom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Histology
Histology, also known as microscopic anatomy or microanatomy, is the branch of biology which studies the microscopic anatomy of biological tissues. Histology is the microscopic counterpart to gross anatomy, which looks at larger structures visible without a microscope. Although one may divide microscopic anatomy into ''organology'', the study of organs, ''histology'', the study of tissues, and ''cytology'', the study of cells, modern usage places all of these topics under the field of histology. In medicine, histopathology is the branch of histology that includes the microscopic identification and study of diseased tissue. In the field of paleontology, the term paleohistology refers to the histology of fossil organisms. Biological tissues Animal tissue classification There are four basic types of animal tissues: muscle tissue, nervous tissue, connective tissue, and epithelial tissue. All animal tissues are considered to be subtypes of these four principal tissue types ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maniraptoromorpha
Maniraptoromorpha is a clade of coelurosaurian theropod dinosaurs that includes taxa such as ''Ornitholestes'', Compsognathidae and Maniraptoriformes. There have been several phylogenetic analyses that have shown support in the grouping of Maniraptoriformes with at least the aforementioned ''Ornitholestes''. This group was named by Andrea Cau, who defined it as the "most inclusive clade containing ''Vultur gryphus'' Linnaeus, 1758, and excluding ''Tyrannosaurus rex'' Osborn, 1905." This group of coelurosaurs according to Cau (2018) has the following synapomorphies: Keel or carinae in the postaxial cervical centra, absence of hyposphene-hypantra in caudal vertebrae (reversal to the plesiomorphic theropodan condition), a prominent dorsomedial process on the semilunate carpal, a convex ventral margin of the pubic foot, a subrectangular distal end of tibia and a sulcus along the posterior margin of the proximal end of fibula. In 2019 Hendrickx ''et al.'' established th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
