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Ornithurae
Ornithurae (meaning "bird tails" in Greek) is a natural group which includes the common ancestor of ''Ichthyornis'', ''Hesperornis'', and all modern birds as well as all other descendants of that common ancestor. Classification Ernst Haeckel coined the name in 1866 and included in the group all "true birds" with the "characteristic tail morphology of all extant birds" (translation by Jacques Gauthier). This distinguishes the group from ''Archaeopteryx'', which Haeckel placed in another new group called Sauriurae. Said simply, modern birds have short, fused pygostyle tails, while ''Archaeopteryx'' retained the long tail characteristic of non-avian theropod dinosaurs.Haeckel, Ernst (1866). ''Generelle Morphologie der Organismen''. Berlin: Georg Reimer. Gauthier converted Ornithurae into a clade, giving it a branch-based definition: "extant birds and all other taxa, such as ''Ichthyornis'' and Hesperornithes, that are closer to extant birds than is ''Archaeopteryx''". Later he and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hesperornithes
Hesperornithes is an extinct and highly specialized group of aquatic avialans closely related to the ancestors of modern birds. They inhabited both marine and freshwater habitats in the Northern Hemisphere, and include genera such as ''Hesperornis'', ''Parahesperornis'', ''Baptornis'', ''Enaliornis'', and ''Potamornis'', all strong-swimming, predatory divers. Many of the species most specialized for swimming were completely flightless. The largest known hesperornithean, ''Canadaga arctica'', may have reached a maximum adult length of . Hesperornitheans were the only Mesozoic avialans to colonize the oceans. They were wiped out in the Cretaceous–Paleogene extinction event, along with enantiornitheans and all other non-avian dinosaurs, and many other diverse plant and animal groups. Anatomy and ecology Most of what is known about this group rests on analyses of single species, as few provide sufficiently complete fossils for analysis. Although some of the smaller and more basal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bird
Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweight skeleton. Birds live worldwide and range in size from the bee hummingbird to the ostrich. There are about ten thousand living species, more than half of which are passerine, or "perching" birds. Birds have whose development varies according to species; the only known groups without wings are the extinct moa and elephant birds. Wings, which are modified forelimbs, gave birds the ability to fly, although further evolution has led to the loss of flight in some birds, including ratites, penguins, and diverse endemic island species. The digestive and respiratory systems of birds are also uniquely adapted for flight. Some bird species of aquatic environments, particularly seabirds and some waterbirds, have further evolved for swimming. B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ichthyornis Dispar
''Ichthyornis'' (meaning "fish bird", after its fish-like vertebrae) is an extinct genus of toothy seabird-like ornithuran from the late Cretaceous period of North America. Its fossil remains are known from the chalks of Alberta, Alabama, Kansas ( Greenhorn Limestone), New Mexico, Saskatchewan, and Texas, in strata that were laid down in the Western Interior Seaway during the Turonian through Campanian ages, about 95–83.5 million years ago. ''Ichthyornis'' is a common component of the Niobrara Formation fauna, and numerous specimens have been found. ''Ichthyornis'' has been historically important in shedding light on bird evolution. It was the first known prehistoric bird relative preserved with teeth, and Charles Darwin noted its significance during the early years of the theory of evolution. ''Ichthyornis'' remains important today as it is one of the few Mesozoic era ornithurans known from more than a few specimens ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bird
Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweight skeleton. Birds live worldwide and range in size from the bee hummingbird to the ostrich. There are about ten thousand living species, more than half of which are passerine, or "perching" birds. Birds have whose development varies according to species; the only known groups without wings are the extinct moa and elephant birds. Wings, which are modified forelimbs, gave birds the ability to fly, although further evolution has led to the loss of flight in some birds, including ratites, penguins, and diverse endemic island species. The digestive and respiratory systems of birds are also uniquely adapted for flight. Some bird species of aquatic environments, particularly seabirds and some waterbirds, have further evolved for swimming. B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ichthyornis
''Ichthyornis'' (meaning "fish bird", after its fish-like vertebrae) is an extinct genus of toothy seabird-like ornithuran from the late Cretaceous period of North America. Its fossil remains are known from the chalks of Alberta, Alabama, Kansas (Greenhorn Limestone), New Mexico, Saskatchewan, and Texas, in strata that were laid down in the Western Interior Seaway during the Turonian through Campanian ages, about 95–83.5 million years ago. ''Ichthyornis'' is a common component of the Niobrara Formation fauna, and numerous specimens have been found. ''Ichthyornis'' has been historically important in shedding light on bird evolution. It was the first known prehistoric bird relative preserved with teeth, and Charles Darwin noted its significance during the early years of the theory of evolution. ''Ichthyornis'' remains important today as it is one of the few Mesozoic era ornithurans known from more than a few specimens ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vegaviidae
Vegaviidae is an extinct family of ornithurines, often regarded as stem-anseriforms, which existed during the Late Cretaceous and possibly the Paleocene. Fossils attributed to the family have been found in Canada, Chile, New Zealand, and Antarctica. Previously the genera ''Neogaeornis'' and '' Polarornis'' were classified as stem-loons based on the similarities in the anatomy of the leg structure.Hope, S. (2002). "The Mesozoic radiation of Neornithes." Pp. 339-388 in Chiappe, L.M. and Witmer, L. (eds.), ''Mesozoic Birds: Above the Heads of Dinosaurs''.Carolina Acosta Hospitaleche, Javier N. Gelfo, New Antarctic findings of Upper Cretaceous and lower Eocene loons (Aves: Gaviiformes), Annales de Paléontologie Volume 101, Issue 4, October–December 2015, Pages 315–324 However, there were some criticism to these assertions as the material are from incomplete specimens from Antarctica lacking several important loon characteristics.Feduccia, A. (1999). ''The Origin and Evolution of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ichthyornithes
Ichthyornithes is an extinct group of toothed avialans very closely related to the common ancestor of all modern birds. They are known from fossil remains found throughout the late Cretaceous period of North America, though only two genera, ''Ichthyornis'' and '' Janavis'', are represented by complete enough fossils to have been named. Ichthyornitheans became extinct at the Cretaceous–Paleogene boundary, along with enantiornitheans, all other non-avian dinosaurs, and many other animal and plant groups. Origin and evolution The earliest known ichthyornitheans appear in the fossil record about 95 million years ago, during the Cenomanian age of the Late Cretaceous. Based on fragmentary fossil remains, the two known species present in the Ashville Formation have not been given names, but overall were very similar to ''Ichthyornis dispar''. ''I. dispar'' itself had a very long temporal range, and specimens referred to it or very similar species existed relatively unchanged (other ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pygostyle
Pygostyle describes a skeletal condition in which the final few caudal vertebrae are fused into a single ossification, supporting the tail feathers and musculature. In modern birds, the rectrices attach to these. The pygostyle is the main component of the uropygium, a structure colloquially known as the bishop's nose, parson's nose, pope's nose, or sultan's nose. This is the fleshy protuberance visible at the posterior end of a bird (most commonly a chicken or turkey) that has been dressed for cooking. It has a swollen appearance because it also contains the uropygial gland that produces preen oil. Evolution Pygostyles probably began to evolve very early in the Cretaceous period, perhaps 140 – 130 million years ago. The earliest known species to have evolved a pygostyle were members of the Confuciusornithidae. The structure provided an evolutionary advantage, as a completely mobile tail as found in species such as '' Archaeopteryx'' is detrimental to its use for flight contro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apatornis
''Apatornis'' is a genus of prehistoric birds endemic to North America during the late Cretaceous. It currently contains a single species, ''Apatornis celer'', which lived around the Santonian-Campanian boundary, dated to about 83.5 million years ago. The remains of this species were found in the Smoky Hill Chalk of the Niobrara Formation in Kansas, United States. It is known from a single fossil specimen: a ''synsacrum'', the fused series of vertebrae over the hips. While the known fossil remains are very incomplete, enough has been found to reasonably estimate that the body length of this bird was between . The type specimen of ''A. celer'', YPM 1451, was reportedly discovered by Othniel Charles Marsh in October 1872 at Butte Creek in Logan County, Kansas. This location is now recognized as falling between Marker Units 15 and 19 of the Smoky Hill Chalk geological formation. An additional, more complete specimen had also been referred to ''Apatornis celer'' by Marsh.O. C. Mars ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cerebavis
''Cerebavis'' is a genus of bird that lived during the Middle Cenomanian (late Cretaceous) period, 99.6 - 93.5 Ma ago, and is known from a single brain mold found in the Melovatskaya Formation of Volgograd Region in Russia. Once considered most likely a member of the Enantiornithes, it is notable for its unusual brain, which displays some unusual features, including a well-developed olfactory system and large cerebrum, suggesting it had a well-developed sense of smell. Although fossils seldom preserve deep-brain soft anatomy, the brain of ''Cerebavis cenomanica'' may show a relatively large parietal eye and pineal gland. In 2015, a reappraisal of the specimen concluded that it belonged to an ornithurine instead of an enantiornithean. In 2021, a redescription of ''Borogovia'' found it to be a possible scansoriopterygid, which is recovered at the base of the non-avialan clade Oviraptorosauria Oviraptorosaurs ("egg thief lizards") are a group of feathered maniraptoran dinosaurs fr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antarcticavis
''Antarcticavis'' (meaning " Antarctic bird") is an extinct genus of avialans of uncertain phylogenetic placement, possibly a member of Ornithuromorpha belonging to the group Ornithurae. It is known from a partial skeleton which was discovered in the Snow Hill Island Formation in Antarctica. The type and only species, ''Antarcticavis capelambensis'', was announced in 2019 although the final version of the article naming it was published in 2020. The holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of sever ..., SDSM 78147, consists of two thoracic vertebrae, the sternum keel, the right coracoid and shoulder blade, the sternal part of the left coracoid, the right upper arm, parts of the left upper arm, the proximal right ulna, the proximal left ulna and radius (articulated), the pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sauriurae
Sauriurae (meaning "lizard tails" in Greek) is a now-deprecated subclass of birds created by Ernst Haeckel in 1866. It was intended to include '' Archaeopteryx'' and distinguish it from all other birds then known, which he grouped in the sister-group Ornithurae ("bird tails"). The distinction Haeckel referred to in this name is that ''Archaeopteryx'' possesses a long, reptile-like tail, while all other birds known to him had short tails with few vertebrae, fused at the end into a pygostyle.Haeckel, Ernst. (1866) "Generelle Morphologie der Organismen" Berlin: Georg Reimer. 462 pp. The unit was not much referred to, and when Hans Friedrich Gadow in 1893 erected Archaeornithes for basically the same fossils, this became the common name for the early reptile-like grade of birds. Ji Qiang and Larry Martin have continued to refer to the Sauriurae as a valid natural group.Ji, Q., and Ji, S. (1996). "On discovery of the earliest bird fossil in China and the origin of birds." ''Chinese ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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