Legless lizards are found in every continent, except Antarctica. Unlike most lizards, the female takes care of the eggs until they hatch, while some species of glass lizards even give birth to young ones.
If you were asked to name an animal which is long, slithery, and without legs, your immediate answer would be - a snake. However, you may need to check again, as it can also be a legless lizard. Legless lizards have evolved from the normal legged lizards that we are familiar with.
The legless lizards, or glass lizards as they are called, are often confused with snakes because of the similarities between the two species. Both possess long, slim, scaly, and cylindrical bodies. They have forked tongues and slither around in sand. The behavioral aspects of snakes and legless lizards are also alike. Both lay eggs that mature outside the body. The eating habits too are pretty similar, with both eating mice and bird eggs.
However, there are some differences between these two species, that distinguish a legless lizard from a snake, which are described below.
Legless Lizards vs. Snakes
Legless lizards have movable eyelids, whereas snakes do not possess eyelids at all.
The jaws of legless lizards are not flexible, and they are unable to open their jaws wide like snakes. Hence, they tend to eat smaller prey like beetles, snails, grasshoppers, and spiders, which are generally smaller than their own heads.
All species of legless lizards have external ear openings, whereas, ears are absent in snakes.
A legless lizard uses its sides to move, which limits its movement from side to side, as opposed to the snake, which can use both its belly scales as well as sides for motion. Thus, a snake has a greater range of movement. A legless lizard, due to its inability to expand and contract its belly scales, is unable to move on flat surfaces, like paved roads.
The long tail of a legless lizard makes up almost two-thirds of its entire body length, whereas, the body proportion of a snake is the exact opposite. A snake has a long body, and a shorter tail in comparison.
The tail is the most prized possession of a legless lizard, and if threatened, it will cut off the tail and run away. This is an effective mechanism to distract predators and save its life. The tail often breaks in more than one piece, which may appear like shattering of glass, which is why, these lizards get the name glass lizards. However, only one additional tail can be regenerated by the glass lizard in its lifetime. The regeneration process may take several months or even a year or two, and the regenerated tail is often shorter and paler in appearance.
In 2007, scientists discovered a 95-million year old fossil, that may be a link to the theory of similar ancestry between snakes and legless lizards. The fossil has small, non-functional front limbs, and normal and standard functioning hind legs. This fossil is considered to be the closest relative of the creature that may have bred snakes and legless lizards.
So the next time you come across a long, slithering, limbless creature, be careful and look for the above signs. You will be able to spot the difference and tell whether it is a legless lizard or a snake.