Snakes are elongated, limbless, carnivorous reptiles of the suborder Serpentes. Like all other squamates, snakes are ectothermic, amniote vertebrates covered in overlapping 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. To accommodate their narrow bodies, snakes' paired organs 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 independently evolved elongate bodies without limbs or with greatly reduced limbs at least twenty-five times 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, although this rule is not universal.
The Horned Serpent appears in the mythologies of many cultures including Native American peoples, European, and Near Eastern mythology. Details vary among cultures, with many of the stories associating the mystical figure with water, rain, lightning, thunder, and rebirth. Horned Serpents were major components of the Southeastern Ceremonial Complex of North American prehistory.
Crotalus cerastes, known as the sidewinder, horned rattlesnake or sidewinder rattlesnake, is a pit viper species belonging to the genus Crotalus, and is found in the desert regions of the Southwestern United States and northwestern Mexico. Like all other pit vipers, it is venomous. Three subspecies are currently recognized.
The Crotalinae, commonly known as pit vipers, or pit adders, are a subfamily of vipers found in Eurasia and the Americas. Like all other vipers, they are venomous. They are distinguished by the presence of a heat-sensing pit organ located between the eye and the nostril on both sides of the head. Currently, 23 genera and 155 species are recognized: These are also the only viperids found in the Americas. The groups of snakes represented here include rattlesnakes, lanceheads, and Asian pit vipers. The type genus for this subfamily is Crotalus, of which the type species is the timber rattlesnake, C. horridus.
The SnakeBot, also known as a snake robot, is a biomorphic hyper-redundant robot that resembles a biological snake. Snake robots come in many shapes and sizes, from as long as four stories to a medical SnakeBot developed at Carnegie Mellon University that is thin enough to maneuver around organs inside a human chest cavity. Though SnakeBots can very greatly in size and design, there are two qualities that all SnakeBot share. The small cross-section-to-length ratios allow them to move into and maneuver through tight spaces and their ability to change the shape of their bodies allows them to perform a wide range of behaviors, such as climbing stairs or tree trunks. Additionally, many snake robots are constructed by chaining together several independent links. This redundancy can make them resistant to failure because they can continue to operate even if parts of their body are destroyed. Properties such as high terrainability, redundancy, and the possibility of complete sealing of the body of the robot, make snake robots very interesting for practical applications and hence as a research topic. A SnakeBot is different from a snake-arm robot in that the SnakeBot robot types are usually more self-contained, where a snake-arm robot usually has remote mechanicals from the arm itself, possibly connected to a larger system.
Rectilinear locomotion or rectilinear progression is a mode of locomotion most often associated with snakes. In particular, it is associated with heavy-bodied species such as terrestrial African adders, pythons and boas; however, most snakes are capable of it. It is one of at least five forms of locomotion used by snakes, the others being lateral undulation, sidewinding, concertina movement, and slide-pushing. Unlike all other modes of snake locomotion, which include the snake bending its body, the snake flexes its body only when turning in rectilinear locomotion.
Cerastes cerastes, commonly known as the Saharan horned viper or the desert horned viper, is a venomous species of viper native to the deserts of Northern Africa and parts of the Arabian Peninsula and Levant. It is often easily recognized by the presence of a pair of supraocular "horns", although hornless individuals do occur. Three subspecies have been described.
Keeled scales refer to reptile scales that, rather than being smooth, have a ridge down the center that may or may not extend to the tip of the scale, making them rough to the touch. According to Street's (1979) description of European lizards and snakes, in those that have keeled scales the keels are usually stronger in male specimens and are consistently arranged according to the species of reptiles, even though many others do not have them. With European lizards, the dorsal scales are usually well keeled, while those on the flanks are more weakly keeled and those on the belly smooth. Non-European lizards such as Sphaerodactylus macrolepis also display keeled scales.
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.
The black-tailed rattlesnake is a venomous pit viper species found in the southwestern United States and Mexico. Four subspecies are currently recognized, including the nominate subspecies described here.
Cerastes is a genus of small, venomous vipers found in the deserts and semi-deserts of northern North Africa eastward through Arabia and Iran. Three species are currently recognized by ITIS, and an additional recently described species is recognized by the Reptile Database. Common names for members the genus include horned vipers, North African desert vipers, and cerastes vipers.
Terrestrial locomotion has evolved as animals adapted from aquatic to terrestrial environments. Locomotion on land raises different problems than that in water, with reduced friction being replaced by the increased effects of gravity.
Bitis peringueyi, also known as the Peringuey's adder, Peringuey's desert adder or desert sidewinding adder, is a venomous viper species found in Namibia and southern Angola. No subspecies are currently recognized.
Cerastes vipera, common names Sahara sand viper and Avicenna viper, is a viper species endemic to the deserts of North Africa and the Sinai Peninsula. No subspecies are currently recognized. Like all other vipers, it is venomous.
The Persian horned viper, known as the Persian horned viper, false horned viper, and by other common names, is a species of vipers endemic to the Middle East and Asia. Like all other vipers, it is venomous.
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.
Caudal luring is a form of aggressive mimicry characterized by the waving or wriggling of the predator's tail to attract prey. This movement attracts small animals who mistake the tail for a small worm or other small animal. When the animal approaches to prey on the worm-like tail, the predator will strike. This behavior has been recorded in snakes, sharks, and eels.
