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Furcula
The (Latin for "little fork"; : furculae) or wishbone is a forked bone found in most birds and some species of non-avian dinosaurs, and is either an interclavicle or formed by the fusion of the two clavicles. In birds, its primary function is in the strengthening of the thoracic skeleton to withstand the rigors of flight. In birds The furcula works as a strut between a bird's shoulders, and articulates to each of the bird's scapulae. In conjunction with the coracoid and the scapula, it forms a unique structure called the triosseal canal, which houses a strong tendon that connects the supracoracoideus muscles to the humerus. This system is responsible for lifting the wings during the recovery stroke. As the thorax is compressed by the flight muscles during downstroke, the upper ends of the furcula spread apart, expanding by as much as 50% of its resting width, and then contracts. X-ray films of starlings in flight have shown that in addition to strengthening the thorax, the f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bone
A bone is a rigid organ that constitutes part of the skeleton in most vertebrate animals. Bones protect the various other organs of the body, produce red and white blood cells, store minerals, provide structure and support for the body, and enable mobility. Bones come in a variety of shapes and sizes and have complex internal and external structures. They are lightweight yet strong and hard and serve multiple functions. Bone tissue (osseous tissue), which is also called bone in the uncountable sense of that word, is hard tissue, a type of specialised connective tissue. It has a honeycomb-like matrix internally, which helps to give the bone rigidity. Bone tissue is made up of different types of bone cells. Osteoblasts and osteocytes are involved in the formation and mineralisation of bone; osteoclasts are involved in the resorption of bone tissue. Modified (flattened) osteoblasts become the lining cells that form a protective layer on the bone surface. The mine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coelophysidae
Coelophysoidea is an extinct clade of theropod dinosaurs common during the Late Triassic and Early Jurassic periods. They were widespread geographically, probably living on all continents. Coelophysoids were all slender, carnivorous forms with a superficial similarity to the coelurosaurs, with which they were formerly classified, and some species had delicate cranial crests. Sizes range from about 1 to 6 m in length. It is unknown what kind of external covering coelophysoids had, and various artists have portrayed them as either scaly or feathered. Some species may have lived in packs, as inferred from sites where numerous individuals have been found together. Examples of coelophysoids include ''Coelophysis'', ''Procompsognathus'' and '' Liliensternus''. Most dinosaurs formerly referred to as being in the dubious taxon "Podokesauridae" are now classified as coelophysoids. The family Coelophysidae, which is contained within Coelophysoidea, flourished in the Late Triassic and Ea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bird Anatomy
Bird anatomy, or the physiological structure of birds' bodies, shows many unique adaptations, mostly aiding flight. Birds have a light skeletal system and light but powerful musculature which, along with circulatory and respiratory systems capable of very high metabolic rates and oxygen supply, permit the bird to fly. The development of a beak has led to evolution of a specially adapted digestive system. Skeletal system Birds have many bones that are hollow ( pneumatized) with criss-crossing struts or trusses for structural strength. The number of hollow bones varies among species, though large gliding and soaring birds tend to have the most. Respiratory air sacs often form air pockets within the semi-hollow bones of the bird's skeleton. The bones of diving birds are often less hollow than those of non-diving species. Penguins, loons, puffins, and kiwis are without pneumatized bones entirely. Flightless birds, such as ostriches and emus, have pneumatized femurs and, in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diplodocid
Diplodocids, or members of the family Diplodocidae ("double beams"), are a group of sauropod dinosaurs. The family includes some of the longest creatures ever to walk the Earth, including '' Diplodocus'' and '' Supersaurus'', some of which may have reached lengths of up to . Description Diplodocids were generally large animals, even by sauropod standards. Thanks to their long necks and tails, diplodocids were among the longest sauropods, with some species such as '' Supersaurus vivianae'' and '' Diplodocus hallorum'' estimated to have reached lengths of or more. The heaviest diplodocids, such as ''Supersaurus'' and '' Apatosaurus'', may have weighed close to 40 tonnes. However, not all diplodocids were so large; the South American species '' Leinkupal laticauda'' was one of the smallest diplodocids, with an estimated length of only . Their heads, like those of other sauropods, were tiny with the nasal openings on the top of the head (though in life the nostrils themselves would ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allosauroidea
Carnosauria is an extinct group of carnivorous theropod dinosaurs that lived during the Jurassic and Cretaceous periods. While Carnosauria was historically considered largely synonymous with Allosauroidea, some recent studies have revived Carnosauria as clade including both Allosauroidea and Megalosauroidea (which is sometimes recovered as paraphyletic with respect to Allosauroidea), and thus including the majority of non- coelurosaurian members of theropod clade Tetanurae. Other researchers have found Allosauroidea and Megalosauroidea to be unrelated groups.Cau A. (2024)A Unified Framework for Predatory Dinosaur Macroevolution Bollettino della Società Paleontologica Italiana, 63(1): 1-19. Distinctive characteristics of carnosaurs include large eye sockets, a long narrow skull and modifications of the legs and pelvis such as the thigh (femur) being longer than the shin (tibia). Carnosaurs first appeared in the Middle Jurassic around , and the last definitive carnosaur famil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spinosauridae
Spinosauridae (or spinosaurids) is a clade or Family (taxonomy), family of tetanuran theropod dinosaurs comprising ten to seventeen known genera. Spinosaurid fossils have been recovered worldwide, including Africa, Europe, South America, and Asia. Their remains have generally been attributed to the Early Cretaceous, Early to early Late Cretaceous. Spinosaurids were large Bipedalism, bipedal carnivores. Their crocodilian-like skulls were long, low, and narrow, bearing conical teeth with reduced or absent Glossary of dinosaur anatomy#serrations, serrations. The tips of their upper and Glossary of dinosaur anatomy#mandible, lower jaws fanned out into a spoon-shaped structure similar to a Rosette (design), rosette, behind which there was a Glossary of dinosaur anatomy#subnarial gap, notch in the upper jaw that the expanded tip of the lower jaw fit into. The Glossary of dinosaur anatomy#bony nostrils, nostrils of spinosaurids were retracted to a position further back on the head than in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Troodontidae
Troodontidae is a clade of bird-like theropod dinosaurs from the Late Jurassic to Late Cretaceous. During most of the 20th century, troodontid fossils were few and incomplete and they have therefore been allied, at various times, with many dinosaurian lineages. More recent fossil discoveries of complete and articulated specimens (including specimens which preserve feathers, eggs, embryos, and complete juveniles), have helped to increase understanding about this group. Anatomical studies, particularly studies of the most primitive troodontids, like '' Sinovenator'', demonstrate striking anatomical similarities with ''Archaeopteryx'' and primitive dromaeosaurids, and demonstrate that they are relatives comprising a clade called Paraves. Evolution The oldest definitive troodontid known is '' Hesperornithoides'' from the Late Jurassic of Wyoming. The slightly older '' Koparion'' of Utah is only represented by a single tooth, and small maniraptoran teeth from the Middle Jurassic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tyrannosauridae
Tyrannosauridae (or tyrannosaurids, meaning "tyrant lizards") is a family of coelurosaurian theropod dinosaurs that comprises two subfamilies containing up to fifteen genera, including the eponymous ''Tyrannosaurus''. The exact number of genera is controversial, with some experts recognizing as few as three. All of these animals lived near the end of the Cretaceous Period and their fossils have been found only in North America and Asia. Although descended from smaller ancestors, tyrannosaurids were almost always the largest predators in their respective ecosystems, putting them at the apex of the food chain. The largest species was ''Tyrannosaurus rex'', the most massive known terrestrial predator, which measured over in length and according to most modern estimates up to in weight. Tyrannosaurids were bipedal carnivores with massive skulls filled with large teeth. Despite their large size, their legs were long and proportioned for fast movement. In contrast, their arms were ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oviraptoridae
Oviraptoridae is a group of bird-like, herbivorous and omnivorous maniraptoran dinosaurs. Oviraptorids are characterized by their toothless, parrot-like beaks and, in some cases, elaborate crests. They were generally small, measuring between one and two metres long in most cases, though some possible oviraptorids were enormous. Oviraptorids are currently known only from the Late Cretaceous of Asia, with the most well-known species and complete specimens found only in the Gobi Desert of Mongolia and northwestern China. Description The most characteristic feature of this group is the skull structure. Oviraptorids had short snouts and very deep mandibles. Some taxa (such as ''Citipati'', '' Corythoraptor'', ''Rinchenia'') had a midline crest on top of the skull, resembling that of a cassowary. Other distinguishing characteristics include a bony spike intruding on the mandibular fenestra, nostrils placed very high and far back on the snout, an extremely thin bony bar beneath the e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dromaeosauridae
Dromaeosauridae () is a family of feathered coelurosaurian theropod dinosaurs. They were generally small to medium-sized feathered carnivores that flourished in the Cretaceous Period. The name Dromaeosauridae means 'running lizards', from Greek ('), meaning 'running at full speed', 'swift', and ('), meaning 'lizard'. In informal usage, they are often called raptors (after '' Velociraptor''), a term popularized by the film ''Jurassic Park''; several genera include the term "raptor" directly in their name, and popular culture has come to emphasize their bird-like appearance and speculated bird-like behavior. Dromaeosaurid fossils have been found across the globe in North America, Europe, Africa, Asia and South America, with some fossils giving credence to the possibility that they inhabited Australia as well. The earliest body fossils are known from the Early Cretaceous (145–140 million years ago), and they survived until the end of the Cretaceous (Maastrichtian stage, 66 ... [...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] |
