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Beak
The beak, bill, or rostrum is an external anatomical structure found mostly in birds, but also in turtles, non-avian dinosaurs and a few mammals. A beak is used for eating, preening, manipulating objects, killing prey, fighting, probing for food, courtship, and feeding young. The terms ''beak'' and '' rostrum'' are also used to refer to a similar mouth part in some ornithischians, pterosaurs, cetaceans, dicynodonts, anuran tadpoles, monotremes (i.e. echidnas and platypuses, which have a beak-like structure), sirens, pufferfish, billfishes and cephalopods. Although beaks vary significantly in size, shape, color and texture, they share a similar underlying structure. Two bony projections – the upper and lower mandibles – are covered with a thin keratinized layer of epidermis known as the rhamphotheca. In most species, two holes called ''nares'' lead to the respiratory system. Etymology Although the word "beak" was, in the past, generally restricted to the sharpened bills o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cephalopod Beak
All extant taxon, extant cephalopods have a two-part beak, or Rostrum (anatomy), rostrum, situated in the buccal mass and surrounded by the muscular Cephalopod limb, head appendages. The Dorsal (anatomy), dorsal (upper) mandible fits into the ventral (lower) mandible and together they function in a scissor-like fashion.Young, R.E., M. Vecchione & K.M. Mangold (1999)Cephalopoda Glossary Tree of Life Web Project. The beak may also be referred to as the mandibles or jaws.Tanabe, K., Y. Hikida & Y. Iba (2006). Two coleoid jaws from the Upper Cretaceous of Hokkaido, Japan. ''Journal of Paleontology'' 80(1): 138–145. Fossilised remains of beaks are known from a number of cephalopod groups, both extant and extinct, including squids, octopuses, belemnites, and vampyromorphs. aptychus, Aptychi – paired plate-like structures found in ammonites – may also have been jaw elements. Composition Composed primarily of chitin and cross-linked proteins, beaks are more-or-less indigestible a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetraodontidae
Tetraodontidae is a family of primarily marine and estuarine fish of the order Tetraodontiformes. The family includes many familiar species variously called pufferfish, puffers, balloonfish, blowfish, blowies, bubblefish, globefish, swellfish, toadfish, toadies, toadle, honey toads, Haaris Anwar fish, sugar toads, and sea squab. They are morphologically similar to the closely related porcupinefish, which have large external spines (unlike the thinner, hidden spines of the Tetraodontidae, which are only visible when the fish have puffed up). The scientific name refers to the four large teeth, fused into an upper and lower plate, which are used for crushing the hard shells of crustaceans and mollusks, their natural prey. The majority of pufferfish species are toxic and some are among the most poisonous vertebrates in the world. In certain species, the internal organs, such as the liver, and sometimes the skin, contain tetrodotoxin, and are highly toxic to most animals when ea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Skull
The skull is a bone protective cavity for the brain. The skull is composed of four types of bone i.e., cranial bones, facial bones, ear ossicles and hyoid bone. However two parts are more prominent: the cranium and the mandible. In humans, these two parts are the neurocranium and the viscerocranium ( facial skeleton) that includes the mandible as its largest bone. The skull forms the anterior-most portion of the skeleton and is a product of cephalisation—housing the brain, and several sensory structures such as the eyes, ears, nose, and mouth. In humans these sensory structures are part of the facial skeleton. Functions of the skull include protection of the brain, fixing the distance between the eyes to allow stereoscopic vision, and fixing the position of the ears to enable sound localisation of the direction and distance of sounds. In some animals, such as horned ungulates (mammals with hooves), the skull also has a defensive function by providing the mount (on the front ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bone
A bone is a Stiffness, rigid Organ (biology), organ that constitutes part of the skeleton in most vertebrate animals. Bones protect the various other organs of the body, produce red blood cell, red and white blood cells, store minerals, provide structure and support for the body, and enable animal locomotion, 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 Function (biology), functions. Bone tissue (osseous tissue), which is also called bone in the mass noun, uncountable sense of that word, is hard tissue, a type of specialized connective tissue. It has a honeycomb-like matrix (biology), 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 mineralization (biology), mineralization of bone; osteoclasts are involved in the bone resorption, resor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gull Beak IMG 1575
Gulls, or colloquially seagulls, are seabirds of the family Laridae in the suborder Lari. They are most closely related to the terns and skimmers and only distantly related to auks, and even more distantly to waders. Until the 21st century, most gulls were placed in the genus ''Larus'', but that arrangement is now considered polyphyly, polyphyletic, leading to the resurrection of several genera. An older name for gulls is mews, which is cognate with German ''Möwe'', Danish ''måge'', Swedish ''mås'', Dutch ''meeuw'', Norwegian ''måke''/''måse'' and French ''mouette'', and can still be found in certain regional dialects. Gulls are typically medium to large in size, usually grey or white, often with black markings on the head or wings. They typically have harsh wailing or squawking calls; stout, longish bills; and webbed feet. Most gulls are ground-nesting carnivores which take live food or scavenge opportunistically, particularly the ''Larus'' species. Live food often inclu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Four-bar Linkage
In the study of mechanisms, a four-bar linkage, also called a four-bar, is the simplest closed- chain movable linkage. It consists of four bodies, called ''bars'' or ''links'', connected in a loop by four joints. Generally, the joints are configured so the links move in parallel planes, and the assembly is called a ''planar four-bar linkage''. Spherical and spatial four-bar linkages also exist and are used in practice. Planar four-bar linkage Planar four-bar linkages are constructed from four links connected in a loop by four one- degree-of-freedom joints. A joint may be either a revolute joint – also known as a pin joint or hinged joint – denoted by R, or a prismatic joint – also known as a sliding pair – denoted by P. A link that are fixed in place relative to the viewer is called a ''ground link.'' A link connecting to the ground by a revolute joint that can perform a complete revolution is called a '' crank link.'' A link connecting to the ground by a revolute join ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Connective Tissue
Connective tissue is one of the four primary types of animal tissue, along with epithelial tissue, muscle tissue, and nervous tissue. It develops from the mesenchyme derived from the mesoderm the middle embryonic germ layer. Connective tissue is found in between other tissues everywhere in the body, including the nervous system. The three meninges, membranes that envelop the brain and spinal cord are composed of connective tissue. Most types of connective tissue consists of three main components: elastic and collagen fibers, ground substance, and cells. Blood, and lymph are classed as specialized fluid connective tissues that do not contain fiber. All are immersed in the body water. The cells of connective tissue include fibroblasts, adipocytes, macrophages, mast cells and leucocytes. The term "connective tissue" (in German, ''Bindegewebe'') was introduced in 1830 by Johannes Peter Müller. The tissue was already recognized as a distinct class in the 18th century. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trabecula
A trabecula (plural trabeculae, from Latin for "small beam") is a small, often microscopic, tissue element in the form of a small beam, strut or rod that supports or anchors a framework of parts within a body or organ. A trabecula generally has a mechanical function, and is usually composed of dense collagenous tissue (such as the trabecula of the spleen). It can be composed of other material such as muscle and bone. In the heart, muscles form trabeculae carneae and septomarginal trabeculae. Cancellous bone is formed from groupings of trabeculated bone tissue. In cross section, trabeculae of a cancellous bone can look like septa, but in three dimensions they are topologically distinct, with trabeculae being roughly rod or pillar-shaped and septa being sheet-like. When crossing fluid-filled spaces, trabeculae may offer the function of resisting tension (as in the penis, see for example trabeculae of corpora cavernosa and trabeculae of corpus spongiosum) or providing a cell fi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Three-dimensional Space
Three-dimensional space (also: 3D space, 3-space or, rarely, tri-dimensional space) is a geometric setting in which three values (called ''parameters'') are required to determine the position (geometry), position of an element (i.e., Point (mathematics), point). This is the informal meaning of the term dimension. In mathematics, a tuple of Real number, numbers can be understood as the Cartesian coordinates of a location in a -dimensional Euclidean space. The set of these -tuples is commonly denoted \R^n, and can be identified to the -dimensional Euclidean space. When , this space is called three-dimensional Euclidean space (or simply Euclidean space when the context is clear). It serves as a model of the physical universe (when relativity theory is not considered), in which all known matter exists. While this space remains the most compelling and useful way to model the world as it is experienced, it is only one example of a large variety of spaces in three dimensions called ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chouette Crâne (2)
Chouette is a French word meaning "owl" which has other uses. ; Species of owl * Chouette D'Ussher, the Rufous fishing owl (''Scotopelia ussheri'') ; Uses relating to owls * La chouette, a character portraying an owl in the opera ''L'enfant et les sortilèges'' by French composer Maurice Ravel * "La chouette", a song by French composer Jeanne Herscher-Clément * ''La chouette'', a series of short CGI-animated episodes for children's television; see The Owl (TV series), ''The Owl'' (TV series) * ''La chouette aveugle'', the original French name of The Blind Owl (film), ''The Blind Owl'' (film) of 1987 * La chouette d'or, a French treasure hunt created by Régis Hauser in 1993; see the Golden Owl quest * "La chouette hulotte" (the tawny owl), a piece for solo piano in ''Catalogue d'oiseaux'' (195658) by French composer Olivier Messiaen * ''Le cri de la chouette'', an autobiographical novel of 1972 by Hervé Bazin * ''Girouette la chouette'', a children's book of 2007 by Nicole Tourneu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Middle English
Middle English (abbreviated to ME) is a form of the English language that was spoken after the Norman conquest of 1066, until the late 15th century. The English language underwent distinct variations and developments following the Old English period. Scholarly opinion varies, but the ''Oxford English Dictionary'' specifies the period when Middle English was spoken as being from 1150 to 1500. This stage of the development of the English language roughly followed the High to the Late Middle Ages. Middle English saw significant changes to its vocabulary, grammar, pronunciation, and orthography. Writing conventions during the Middle English period varied widely. Examples of writing from this period that have survived show extensive regional variation. The more standardized Old English language became fragmented, localized, and was, for the most part, being improvised. By the end of the period (about 1470) and aided by the invention of the printing press by Johannes Gutenberg in 14 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
