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Canthus (snake)
In snakes and amphibians, the canthus, canthal ridge or ''canthus rostralis'',Spawls S, Branch B. 1995. ''The Dangerous Snakes of Africa''. Ralph Curtis Books. Dubai: Oriental Press. 192 pp. . is the angle between the flat crown of the head and the side of the head between the eye and the snout,Mallow D, Ludwig D, Nilson G. 2003. ''True Vipers: Natural History and Toxinology of Old World Vipers''. Krieger Publishing Company, Malabar, Florida. . or more specifically, between the supraocular scale and the rostral scale. It is defined as a sharp ridge in many viperids, but is rounded in most rattlesnakes Rattlesnakes are venomous snakes that form the genera ''Crotalus'' and ''Sistrurus'' of the subfamily Crotalinae (the pit vipers). All rattlesnakes are vipers. Rattlesnakes are predators that live in a wide array of habitats, hunting small anima ..., for example.Campbell JA, Lamar WW. 2004. The Venomous Reptiles of the Western Hemisphere. Comstock Publishing Associates, Ithaca and Lo ... [...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] |
Amphibia
Amphibians are four-limbed and ectothermic vertebrates of the class Amphibia. All living amphibians belong to the group Lissamphibia. They inhabit a wide variety of habitats, with most species living within terrestrial, fossorial, arboreal or freshwater aquatic ecosystems. Thus amphibians typically start out as larvae living in water, but some species have developed behavioural adaptations to bypass this. The young generally undergo metamorphosis from larva with gills to an adult air-breathing form with lungs. Amphibians use their skin as a secondary respiratory surface and some small terrestrial salamanders and frogs lack lungs and rely entirely on their skin. They are superficially similar to reptiles like lizards but, along with mammals and birds, reptiles are amniotes and do not require water bodies in which to breed. With their complex reproductive needs and permeable skins, amphibians are often ecological indicators; in recent decades there has been a dramatic decl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supraocular Scale
In scaled reptiles, supraocular scales are (enlarged) scales on the crown immediately above the eye.Mallow D, Ludwig D, Nilson G. 2003. True Vipers: Natural History and Toxinology of Old World Vipers. Malabar, Florida: Krieger Publishing Company. 359 pp. . The size and shape of these scales are among the many characteristics used to differentiate species from each another. In many species of boids and viperids, the supraoculars are heavily fragmented. In others, such as the colubrids and elapids, they are enlarged. See also * Ocular scales * Snake scales * Anatomical terms of location Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position pro ... References {{Reflist Snake scales ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rostral Scale
The rostral scale, or rostral, in snakes and other scaled reptiles is the median plate on the tip of the snout that borders the mouth opening. Wright AH, Wright AA (1957). ''Handbook of Snakes of the United States and Canada''. Ithaca and London: Comstock Publishing Associates. (7th printing, 1985). 1,105 pp. (in two volumes). . It corresponds to the mental scale in the lower jaw. The term pertains to the rostrum, or nose. In snakes, the shape and size of this scale is one of many characteristics used to differentiate species from one another. Related scales *Nasorostral scale *Mental scale *Labial scales See also *Snake scales *Anatomical terms of location Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position pro ... References {{Reflist Snake scales ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Viperidae
The Viperidae (vipers) are a family of snakes found in most parts of the world, except for Antarctica, Australia, Hawaii, Madagascar, and various other isolated islands. They are venomous and have long (relative to non-vipers), hinged fangs that permit deep penetration and injection of their venom. Four subfamilies are currently recognized. They are also known as viperids. The name "viper" is derived from the Latin word ''vipera'', -''ae'', also meaning viper, possibly from ''vivus'' ("living") and ''parere'' ("to beget"), referring to the trait viviparity (giving live birth) common in vipers like most of the species of Boidae. Description All viperids have a pair of relatively long solenoglyphous (hollow) fangs that are used to inject venom from glands located towards the rear of the upper jaws, just behind the eyes. Each of the two fangs is at the front of the mouth on a short maxillary bone that can rotate back and forth. When not in use, the fangs fold back against the ro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crotalus
''Crotalus'' is a genus of venomous pit vipers in the family Viperidae, known as rattlesnakes or rattlers.Albert Hazen WWright AH, Wright AA (1957). ''Handbook of Snakes of the United States and Canada''. Ithaca and London: Comstock Publishing Associates (7th printing, 1985). 1,105 pp. (in 2 volumes). . The genus is found only in the Americas from southern Canada to northern Argentina, and member species are colloquially known as rattlesnakes. The Genus, generic name ''Crotalus'' is derived from the Greek word ''krótalοn'', which means "rattle" or "castanet", and refers to the rattle on the end of the tail, which makes this group (genera ''Crotalus'' and ''Sistrurus'') so distinctive.Campbell JA, Lamar WW (2004). ''The Venomous Reptiles of the Western Hemisphere''. Ithaca and London: Comstock Publishing Associates. 870 pp. 1,500 plates. . Currently, 32 to 45 species are recognized as being valid. Description Members of the genus ''Crotalus'' range in size from only (''Crotal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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