Why Don’t Snakes Have Legs?

Just because snakes do not have legs now, does not mean they did not have them at sometime in their development. But how and why they came to lose their legs is not known to science.

Some experts believe that the ancestors of snake were certain kinds of burrowing lizards. There are many kinds of such lizards today, and all of them have very small legs or no legs at all.  

In time, the legs disappeared altogether. And despite this, snakes are able to move and get along very well indeed. One of the most helpful things for them in moving are the belly scales that cover the entire undersurface of most snakes.

There are four ways in which snakes move. One of them is called “lateral undulatory movement”. in this method, ths snake forms its body into a number of wavy, S-shaped curves. By pressing backward and outward against rough places on the ground, the snake slips forward on those scales.

A second way snakes move is called “rectilinear movement”. in this case, small groups of the belly scales are pulled forward on part of the body, while other scales project backward to keep the snake from slipping back.

Then the scales that have been holding the body are pulled forward. The scales that moved first hold the body. A third way is a “concertina” method, which is used for climbing.

The snake wraps its tail and rear part of the body around a tree, stretches out the forepart of its body and hooks it on the tree higher up. Then it releases the rear part and hooks it on the tree higher up. Then it relases the rear part and pulls the rest of its body upwards.

“Sidewinding” is another method by which snakes move. A loop of the forebody is thrown to one side. Then the rear parts is shifted to the new position, and another neck loop is thrown out.

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