The Elipidae family is found in warm regions and contains the cobras and coral snakes, both that are venomous. Cobras are well known for their wide neck hood, which is not displayed most the time. It appears when they want to scare off predators. In Australia, nine out of every ten snakes are a cobra, which is quite frightening. The last major group is the Viperidae. They are the latest group of snakes to evolve. In addition, their poison apparatus seems to be the most developed. Their fangs are curled up until they are ready to be used. There are two divisions in this family. There are the Vipernane, which are the true vipers, and there are the Crotalinane, which includes the rattlesnakes and their allies. .
The body of a snake is quite amazing. The snake has to carry all its internal organs in a long and narrow body cavity. The intestines and the gut fit in very easily because they are long and skinny. However the organs that come in pairs such as the lungs and the kidneys are much harder to accommodate. Therefore, they are either put one behind the other or one of the pair is eliminated completely. The kidneys, testes, and ovaries are all arranged this way with one behind the other. There are two lungs but the right one is very small and barely used. The blood system of the snake is much like that of other reptiles. The most important adaptation in snakes is the amount of vertebrae. In order to have the flexibility that they need they have many vertebrae with much flexibility. Snakes have between 180 - 400 vertebrae, with all of them being the same size. This large number also gives it a stronger vertebral column and lessens the likelihood of damage to the spinal cord.
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The question of how snakes move has baffled people for all time. We watch them and wonder. Snakes have several means of propulsion. It is a lot easier for them to do it them for us to understand how it is done. The basic mean of locomotion is by wriggling the body using complicated muscles ranges extending down on either side of the backbone.