World Snake Day | Nine questions about snakes, here are the answers!

"Walking without feet, swimming without fins, flying without wings", this ancient riddle is not difficult. It accurately and concisely summarizes the body structure and movement of snakes. July 16th every year is World Snake Day. I believe you have many "little questions" about snakes. Let's explore the mysteries of snake evolution and life together!

A full skeleton specimen of a king cobra (Ophiophagus hannah) on display at the Zhejiang Museum of Natural History (produced by Shi Jingsong and photographed by Chen Yining)

Q1 : How did the snake lose its “ hands and feet ”?

The appearance of snakes can be regarded as an "episode" in the evolutionary history of vertebrates. The snakes' bodies became longer, and their vertebrae and ribs increased. How they lost their limbs is still a hot scientific question. The current mainstream view is that they evolved to adapt to underground life.

Q2: When did the first snake appear on Earth?

It is generally believed that the earliest snakes in the world appeared in the Middle Jurassic period, about 170 to 160 million years ago. It can be said that snakes are reptiles that walked with dinosaurs.

Q3: Do all snakes have no limbs?

In more basic (primitive) snakes, such as pythons and tubifex, their hind limbs have not completely degenerated. On both sides of the cloaca at the rear end of their bodies (where the tail is located), there are still remnants of small claw-like hind limbs. These "hind limbs" no longer have the ability to move, but only play an auxiliary role in grasping during mating.

Q4: How can a snake swallow something so big?

The reason why snakes can swallow prey wider than themselves is not because their upper and lower jaws can be dislocated at will, but because there are two flexible bones on each side between the snake's skull and the lower jaw, so they can open a large angle. Although the upper and lower jaws of snakes cannot be easily separated, the lower jaws on both sides can be separated from each other, and the skin of the mouth and neck is loose and can expand to a large extent.

Q5: Who is the "pinnacle" of snake evolution history?

If you ask which is the most "advanced" group in the history of snake evolution, it must be the "pit vipers". Snakes of the subfamily Viperinae can be said to have a variety of elite "strategic equipment" in one: tubular fangs, highly effective venom, and sophisticated infrared sensors.

Q6: Are snakes extremely vicious animals?

Snakes are not vicious animals. The fear of snakes towards humans is much greater than the fear of humans towards snakes. Most snakes' first reaction when seeing humans is to quickly flee. They will only bite humans when they are captured, trampled, or cornered.

Q7: Will snakes eat people?

Can snakes eat people? Most snakes do not have the habit of eating people. Only in rare cases in some areas of Southeast Asia, giant reticulated pythons will mistake humans for prey, and such incidents are rare in history.

Q8: What image do snakes have in human culture?

In many cultures, snakes are shrouded in mystery. In Chinese legends, Fuxi and Nuwa both have human heads and snake bodies. Western countries also regard snakes as gods. The snake emblem on ambulances is an image of a snake wrapped around a cane.

Q9: What should I do if I encounter a snake in the wild?

If you encounter a snake in the wild, do not tease it! Snakes are usually more afraid of people and will avoid them. If the snake does not flee, you should make way for it. For example, if you are in a mountain, you can walk up to lead it to a lower place. If you encounter a snake in the grass, stamp your feet lightly to drive it away. If that doesn't work, you can use a stick to poke it lightly to avoid hitting it hard. Stay calm and safety first.

Author: Shi Jingsong, PhD in Amphibians and Reptiles, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences

Produced by: Science Popularization China

Produced by: China Science and Technology Press Co., Ltd., China Science and Technology Publishing House (Beijing) Digital Media Co., Ltd.

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