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Concertina Movement
Concertina movement is the movement occurring in snakes and other legless organisms that consists of gripping or anchoring with portions of the body while pulling or pushing other sections in the direction of movement. Mechanism Each point on the snake's body goes through alternating cycles of static contact and movement, with regions propagating posteriorly (i.e. any point on the snake will change from movement to stasis or vice versa shortly after the change occurs in the point anterior to it). This movement is quite strenuous and slow compared to other methods of locomotion. Energetic studies show that it takes more calories per meter to use concertina locomotion than either sidewinding or lateral undulation Undulatory locomotion is the type of motion characterized by wave-like movement patterns that act to propel an animal forward. Examples of this type of gait include crawling in snakes, or swimming in the lamprey. Although this is typically the .... Modes In snakes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Snake
Snakes are elongated, Limbless vertebrate, limbless, carnivore, carnivorous reptiles of the suborder Serpentes . Like all other Squamata, squamates, snakes are ectothermic, amniote vertebrates covered in overlapping Scale (zoology), scales. Many species of snakes have skulls with several more joints than their lizard ancestors, enabling them to swallow prey much larger than their heads (cranial kinesis). To accommodate their narrow bodies, snakes' paired organs (such as kidneys) appear one in front of the other instead of side by side, and most have only one functional lung. Some species retain a pelvic girdle with a pair of vestigial claws on either side of the cloaca. Lizards have evolved elongate bodies without limbs or with greatly reduced limbs about twenty-five times independently via convergent evolution, leading to many lineages of legless lizards. These resemble snakes, but several common groups of legless lizards have eyelids and external ears, which snakes lack, altho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sidewinding
Sidewinding is a type of locomotion unique to snakes, used to move across loose or slippery substrates. It is most often used by the Saharan horned viper, ''Cerastes cerastes'', the Mojave sidewinder rattlesnake, ''Crotalus cerastes'', and the Namib desert sidewinding adder, ''Bitis peringueyi'', to move across loose desert sands, and also by Homalopsine snakes in Southeast Asia to move across tidal mud flats. Any number of caenophidian snakes can be induced to sidewind on smooth surfaces, though the difficulty in getting them to do so and their proficiency at it vary greatly. The method of movement is derived from lateral undulation, and is very similar, in spite of appearances. A picture of a snake performing lateral undulation would show something like a sine wave, with straight segments of the body having either a positive or negative slope. Sidewinding is accomplished by undulating vertically as well as laterally, with the head tracing out an ellipse in a vertical plane n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lateral Undulation
Undulatory locomotion is the type of motion characterized by wave-like movement patterns that act to propel an animal forward. Examples of this type of gait include crawling in snakes, or swimming in the lamprey. Although this is typically the type of gait utilized by limbless animals, some creatures with limbs, such as the salamander, forgo use of their legs in certain environments and exhibit undulatory locomotion. In robotics this movement strategy is studied in order to create novel robotic devices capable of traversing a variety of environments. Environmental interactions In limbless locomotion, forward locomotion is generated by propagating flexural waves along the length of the animal's body. Forces generated between the animal and surrounding environment lead to a generation of alternating sideways forces that act to move the animal forward. These forces generate thrust and drag. Hydrodynamics Simulation predicts that thrust and drag are dominated by viscous forces a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Smithsonian (magazine)
''Smithsonian'' is the official journal published by the Smithsonian Institution in Washington, D.C. The first issue was published in 1970. History The history of ''Smithsonian'' began when Edward K. Thompson, the retired editor of ''Life (magazine), Life'' magazine, was asked by the then-Secretary of the Smithsonian, S. Dillon Ripley, to produce a magazine "about things in which the Smithsonian [Institution] is interested, might be interested or ought to be interested." Thompson would later recall that his philosophy for the new magazine was that it "would stir curiosity in already receptive minds. It would deal with history as it is relevant to the present. It would present art, since true art is never dated, in the richest possible reproduction. It would peer into the future via coverage of social progress and of science and technology. Technical matters would be digested and made intelligible by skilled writers who would stimulate readers to reach upward while not turning the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
