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Apsaravis
''Apsaravis'' is a Mesozoic avialan genus from the Late Cretaceous. The single known species, ''Apsaravis ukhaana'', lived about 78 million years ago, in the Campanian age of the Cretaceous period. Its fossilized remains were found in the Camel's Humps sublocality of the Djadokhta Formation, at Ukhaa Tolgod in the Gobi Desert of Mongolia. They were collected in the 1998 field season by the Mongolian Academy of Sciences/American Museum of Natural History Paleontological Expeditions. It was described by Norell and Clarke (2001).Norell, Mark A., Clarke, Julia A. (2001). "Fossil that fills a critical gap in avian evolution". ''Nature'' Vol. 409 11 January 2001 pp.181-184. Its habitat was presumably very arid open landscape much like it is today, perhaps hotter still and with more (but nonetheless intermittent) rain. Permanent freshwater would have been scarce. Implications ''Apsaravis'' is important in avian paleontology. It has provided evidence that is directly relevant to at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enantiornithes
The Enantiornithes, also known as enantiornithines or enantiornitheans in literature, are a group of extinct Avialae, avialans ("birds" in the broad sense), the most abundant and diverse group known from the Mesozoic era. Almost all retained teeth and clawed fingers on each wing, but otherwise looked much like modern birds externally. Over seventy species of Enantiornithes have been named, but some names represent only single bones, so it is likely that not all are valid. The Enantiornithes became extinct at the Cretaceous–Paleogene boundary, along with Hesperornithes and all other non-avian dinosaurs. Discovery and naming The first Enantiornithes to be discovered were incorrectly referred to modern bird groups. For example, the first known species of Enantiornithes, ''Gobipteryx minuta'', was originally considered a paleognath related to ostriches and tinamou. The Enantiornithes were first recognized as a distinct lineage, or "subclass" of birds, by Cyril A. Walker in 1981. W ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aves
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 common ostrich. There are over 11,000 living species and they are split into 44 orders. More than half are passerine or "perching" birds. Birds have wings 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Confuciusornis
''Confuciusornis'' is a genus of basal crow-sized avialan from the Early Cretaceous Period of the Yixian and Jiufotang Formations of China, dating from 125 to 120 million years ago. Like modern birds, ''Confuciusornis'' had a toothless beak, but closer and later relatives of modern birds such as ''Hesperornis'' and '' Ichthyornis'' were toothed, indicating that the loss of teeth occurred convergently in ''Confuciusornis'' and living birds. It was thought to be the oldest known bird to have a beak, though this title now belongs to an earlier relative '' Eoconfuciusornis''. It was named after the Chinese moral philosopher Confucius (551–479 BC). ''Confuciusornis'' is one of the most abundant vertebrates found in the Yixian Formation, and several hundred complete specimens have been found. History of discovery In November 1993, the Chinese paleontologists Hou Lianhai and Hu Yoaming of the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) at Beijing, visited fos ... [...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 (''archaîos''), 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'', '' Aurornis'', and '' Baminornis''. ''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'' ... [...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 Geolo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ornithurae
Ornithurae (meaning "bird tails" in Greek) is a natural group that includes modern birds and their very close relatives such as the ichthyornithines and the hesperornithines. This clade is defined in the ''PhyloCode'' by Juan Benito and colleagues in 2022 as "the smallest clade containing '' Ichthyornis dispar'', '' Hesperornis regalis'', and '' Vultur gryphus''". 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 defi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theropod
Theropoda (; from ancient Greek , (''therion'') "wild beast"; , (''pous, podos'') "foot"">wiktionary:ποδός"> (''pous, podos'') "foot" is one of the three major groups (clades) of dinosaurs, alongside Ornithischia and Sauropodomorpha. Theropods, both extant and extinct, are characterized by hollow bones and three toes and claws on each limb. They are generally classed as a group of saurischian dinosaurs, placing them closer to sauropodomorphs than to ornithischians. They were ancestrally carnivorous, although a number of theropod groups evolved to become herbivores and omnivores. Members of the subgroup Coelurosauria and possibly some other or all theropods were covered in feathers. In the Jurassic, birds evolved from small specialized coelurosaurian theropods, and are currently represented by about 11,000 living species, making theropods the only group of dinosaurs alive today. Theropods first appeared during the Carnian age of the late Triassic period ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Femur
The femur (; : femurs or femora ), or thigh bone is the only long bone, bone in the thigh — the region of the lower limb between the hip and the knee. In many quadrupeds, four-legged animals the femur is the upper bone of the hindleg. The Femoral head, top of the femur fits into a socket in the pelvis called the hip joint, and the bottom of the femur connects to the shinbone (tibia) and kneecap (patella) to form the knee. In humans the femur is the largest and thickest bone in the body. Structure The femur is the only bone in the upper Human leg, leg. The two femurs converge Anatomical terms of location, medially toward the knees, where they articulate with the Anatomical terms of location, proximal ends of the tibiae. The angle at which the femora converge is an important factor in determining the femoral-tibial angle. In females, thicker pelvic bones cause the femora to converge more than in males. In the condition genu valgum, ''genu valgum'' (knock knee), the femurs conve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fossa (anatomy)
In anatomy, a fossa (; : fossae ( or ); ) is a depression or hollow, usually in a bone, such as the hypophyseal fossa (the depression in the sphenoid bone).Venieratos D, Anagnostopoulou S, Garidou A., A new morphometric method for the sella turcica and the hypophyseal fossa and its clinical relevance.;Folia Morphol (Warsz). 2005 Nov;64(4):240-7. Some examples include: In the skull: * Cranial fossa ** Anterior cranial fossa ** Middle cranial fossa *** Interpeduncular fossa ** Posterior cranial fossa * Hypophyseal fossa * Temporal bone fossa ** Mandibular fossa ** Jugular fossa * Infratemporal fossa * Pterygopalatine fossa * Pterygoid fossa * Lacrimal fossa ** Fossa for lacrimal gland ** Fossa for lacrimal sac * Scaphoid fossa * Condyloid fossa * Rhomboid fossa In the mandible: * Retromolar fossa In the torso: * Fossa ovalis (heart) * Infraclavicular fossa * Pyriform fossa * Substernal fossa * Iliac fossa * Ovarian fossa * Paravesical fossa * Coccygeal f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Condyle
A condyle (; in Merriam-Webster Online Dictionary '. , from ; 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 joint: ** [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ischium
The ischium (; : ischia) is a paired bone forming the lower and back part of the hip bone. Situated below the ilium (bone), ilium and behind the pubis (bone), pubis, it is one of three regions whose fusion creates the coxal bone. The superior portion of this region forms approximately one-third of the acetabulum. Structure The ischium is made up of three parts–the body, the superior ramus and the inferior ramus. The body contains a prominent ischial spine, spine, which serves as the origin for the superior gemellus muscle. The indentation inferior to the spine is the lesser sciatic notch. Continuing down the posterior side, the ischial tuberosity is a thick, rough-surfaced prominence below the lesser sciatic notch. This is the portion ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pubis (bone)
In vertebrates, the pubis or pubic bone () forms the lower and anterior part of each side of the hip bone. The pubis is the most forward-facing ( ventral and anterior) of the three bones that make up the hip bone. The left and right pubic bones are each made up of three sections; a superior ramus, an inferior ramus, and a body. Structure The pubic bone 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 – the mons pubis. The pubis is the lower limit of the suprapubic region. In the female, the pubis is anterior to the urethral sponge. Body The body of pubis has: * a superior border or the pubic crest * a pubic tubercle at the lateral end of the pubic crest * three surfaces (anterior, posterior and medial). The body forms the wide, strong, middle and flat part of the pubic bone. The bodies of the left and right pubic bones join at the pubic symphysis. The r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
