If it is legless and slithers, is it a snake?

What makes a Giant Legless Skink a skink instead of a snake? Why is it often called a “Glass Lizard”?

This might help you to be able to distinguish this lizard from a snake the next time you find yourself looking at a long, slithery, legless reptile!  It’s not unlikely that you’d come into contact with one when out in the bush, since they live all over the world, on every continent except Antartica and can thrive in all sorts of climates — cool, hot, wet and dry.

At first glance the giant legless skink looks an awful lot like a snake, but there are some obvious differences. First, the lizards have movable eyes, which snakes do not have. Perhaps the most interesting difference between the snake and the legless lizard is the fact that the legless lizard can break off its tail when it is threatened or in danger, which is why it is called the glass lizard because it looks like it is shattering when the tail breaks off! Overall, the legless lizard is very fascinating, though often misunderstood and misidentified. Both snakes and skinks have long, cylindrical bodies; forked tongues; scaly exteriors and can often be found slithering through sand. And then, of course, there’s the leglessness. It’s tough for the casual observer to tell them apart but it’s not impossible.

The skink grows to about 45cms in length, has a powerful body, extremely thick around the middle with a short, cylindrical tail.

The broad head has an elongated, steel-grey snout and it has eyelids and ear openings. It is a uniform shiny black to dark brown and has smooth overlapping scales.

Giant Legless Skink close up

 

This species is found in South Africa from the north eastern Limpopo province, extending through Mpumalanga to coastal northern KwaZulu-Natal and the Eastern Cape. It is also found in Swaziland (now called eSwatini), southern Mozambique and there is an isolated relic population that occurs on the eastern escarpment of Zimbabwe.

Being a skink, it is completely harmless to anyone. They bear live young and can have up to 14 at a time.

It can be mistaken at first glance to a mole snake but this snake grows up to 2 metres long!  It gives birth to up to 50 young which are over 20cm in length. The mole snake eats rodents and small mammals just like the skink. Our legless lizard particularly likes snails, grasshoppers and other invertebrates, but would also eat eggs and small vertebrates like mice or lizards. But the Giant legless skink has inflexible jaws so, unlike snakes, they can’t “unlock” their jaws to swallow a whole rabbit or prey much larger than themselves. A legless lizard has to stick to prey that’s smaller than its own head.

Mole Snake

Whereas a snake can use its sides and its belly scales to push itself along the ground, a legless lizard can only use its sides. Its motion is only side-to-side.

Even with all of these differences, the giant legless skink and snakes appear to come from similar beginnings. In 2007, scientists discovered a 95-million-year-old fossil that’s the oldest known proof of the lizard’s evolution to a legless state. This new fossil, called Adriosaurus microbrachis, has tiny, non-functioning front legs, but still-functioning and normal-sized hind legs. The fossil is the same approximate age as snake fossils that have similar vestigial front legs, leading to the conclusion that snakes and lizards lost their legs around the same time.

So next time you see something slithering in the bush that looks like a short,  stubby snake, stand still, take a deep breath and see if it might be a Giant Legless Skink!  And for a chance to explore the wilderness and restore your soul, why not check into a lovely home in the bush at Royal Jozini in exquisite eSwatini!

 

With thanks to livescience.com and howstuffworks.com