How snake move without paws?

Snake anatomy -

How snake move without paws?

Snakes move thanks to their muscles while crawling on the ground. So, not needing paws anymore, evolution has done its job. That's why snakes crawl and don't walk. He bends, pushes with the back of his body, then unfolds. Then he brings his tail back towards his head and starts the same movement again. In addition, the snake knows how to move its belly skin to move forward, a bit like a belly dance.

 

snake rings

 

We won't talk about poison, venom (toxin), or antidote. But about mouvement... to live and survive! Eels swim (also water snakes), hawks soar through the sky (Yes there is not flying snakes), moles dig tunnels, and squirrels jump to scavenge, breed, or escape predators. These feats of locomotion require coordination of complex biophysical processes ⚡, which occur at the molecular scale (molecules control the propagation of information in neurons), at the intermediate scale (muscles and tendons couple with skeletal elements to drive the movement of different parts of the body) and at the large scale (certain parts of the body, such as the feet and hands, interact with their environment to move forward). One of locomotion science goals is to discover general principles of movement through the development of multi-scale models, a challenge that requires the collaboration of biologists, physicists, mathematicians, and engineers. These studies inspire the design of vehicles whose mobility equals or exceeds that of animals.. 

 

little snake

 

Snake bodies are very different between snake species, they lack legs and arms 👋 (Why?!). But their agile bodies are capable of crossing incredibly narrow places. How can this be done?. This ability depends on the combination of flexibility in the spine (vertebrates), a strong musculature 💪, and their ventral scales at the bottom. An adult human has 26 vertebrae in its spine; snakes have more than 400, which allows them to move the trunk much better than humans. Each pair of snake's ribs is attached to one vertebra.

 

snake vertebrae

 

When these reptiles move, the posterior parts of the scales will fix themselves to the ground (grip the surface) to make the opposite movement to the muscles that will drive them forward (anterior part). Snakes move according to the land on which they are; this is a beautiful example of adaptation. We can see their strengths in this area because on any terrain the snake will adapt. A well-known example is the horned rattlesnake 🐍 has its tricks to survive in sandy habitats where it lives. The movement consists of moving forward and then sideways. Its lower body and tail are raised above the hot desert sand, leaving a J-shaped pattern (this can be scary).

Some snakes can climb trees, for example, the Emerald tree boa. To do so, the species in question will wrap itself around the tree and then slide gently like an accordion. The tail helps it cling to the trunk while extending its head forward, taking the momentum to push its body.

 

emerald tree boa

1. Why don't snakes have legs?

Two teams of scientists working on the issue have discovered that the snakes were, in fact, victims of Sonic Hedgehog 🦔. It is not a virus that turns its victims into blue hedgehogs, but a protein that, during the embryonic development of mammals, regulates, among other things, the formation of fingers. This protein had already made a name for itself in the past because scientists shown that it played a decisive role in reducing the size of the lizards' legs. The Sonic Hedgehog impacted the evolution of several reptiles as it is also responsible for the lack of legs in snakes 🐍. Martin Cohn, a biologist at the University of Florida, discovered that proteins had little chance of accessing the Sonic Hedgehog during the python's embryonic stage. Without this, the animal's legs do not develop.

At the same time, Axel Visel (researcher at the Lawrence Berkeley National Laboratory in California) published his research results. After implanting the Sonic Hedgehog in mice, he observed the subsequent litters' development: normal mice had legs while those with the protein had bumps. If you want to know more about this very interesting study we suggest you discover the study in question on the NCBI website. While the gene is not entirely involved in the snakes' mutation, it has played a significant role in its physical evolution. The scientific community has already welcomed the conclusions reached by the two teams. The question "Why don't snakes have legs? "finally seems to answer, although researchers are still working on it to complete it.

 

DNA sonic hesgehog

2. How did the snakes lose their paws?

A Chinese charade invites you to guess who runs without legs, swims without fins, and glides without wings. The answer? The snake 🐍, of course! More than 3,000 current species have, in fact, a limbless body capable of moving on the ground, in the water, and the air from one tree to another. Their oldest ancestors, on the other hand, had limbs of various shapes. Hence the question: how did the snakes lose their legs?

The specialization of limbs is often linked to a type of habitat. The appearance of fins in whales, for example, results from the ancestor's adaptation to the marine environment; similarly, the wings evolved when birds began to move in the air. And in the case of snakes? Evolutionary biologists debated this for decades, probably partly because, while snakes are now widespread, the fossil record 🦖 of the first of them is very small. Nevertheless, the debate has focused on two hypotheses: according to the first, the snakes would have lost their legs by adapting to marine life; according to the second, they would have done so by adapting to life in underground environments.

 

snake fossils



Ah, if we could transport ourselves to the beginning of the snakes' evolution! We could then observe their ancestors in their Cretaceous habitats, 145 million to 66 million years ago ⌛, and determine whether they excelled at swimming or rather at digging burrows. However, we only have fossil remains. It is sometimes difficult to reconstruct an animal's ecology and behavior from its bones alone, especially if they are damaged or fragmented, often with fossils.


In the last ten years, however, advances in imaging techniques have allowed us to understand the origin of snakes (YES!). By using X-ray we have been able to find new characteristics of the snake's bone structure. At the same time, evolutionary developmental biology research elucidated some of the genetic mechanisms by which the snakes' limbs may have disappeared and their vertebrae multiplied. While our understanding of the origin of snakes is far from complete, we understand better and better how they evolved, which we have explained with the Sonic Hedgehog gene 🧬.

Appearing some 85 million years ago (late Cretaceous), Dinilysia Patagonia is the first known legless snake, at a time when dinosaurs still dominated the world. Particularly well preserved, its almost complete skeleton was caught in the rust-colored sandstone of the Patagonian plateau. The species had no limbs, no scapula (shoulder support), or pelvic girdle 🦴 of a size comparable to that of a man.

 

snake bones

 



The oldest known legless snake was larger than today's burrowing reptiles. However, members were present in some species of snakes. The Najash Rionegrina, a terrestrial species in South America, more precisely in Argentina 🌎, 92 million years old, whose representatives are not much longer than a spaghetti, had small hind limbs consisting of bony elements from the hip to the ankle. Much too small and delicate to support the weight of the animal, they would have been used instead to cling to the partner during mating.

The oceans were filled with other legged snakes of the Upper Cretaceous. In the Jerusalem area, marine deposits have yielded fossils of sea snakes, which swam in a sea where sharks also lived. Two of these fossil forms, Pachyrhachis and Haasiophis, were characterized by their almost complete hind limbs, including the thigh, leg, and foot bones 🦵. Their function is unknown (not everything is always known!). As the limbs of the Pachyrhachis and Haasiophis were not connected to the trunk by a pelvic girdle, their legs were of little use for swimming.

3. Who is Dinilysia Patagonia? 

The Genus Dinilysia (Terrible Destroyer) is the oldest known example of snakes, evolving from lizard ancestors about 85 million years ago. It lived in the Upper Cretaceous, and its remains have been discovered in South America, in the Coniaciense of Argentina. This snake reached a length of 1.8 to 3 meters 📏and preyed on small animals. The shape of the animal's skull does not support the idea that snakes were diggers during their origin; it is clear that Dinilysia was terrestrial.

Dialysis was not poisonous and killed its prey by strangulation, like our days' boas (Boa Constrictor)  and pythons. It swallowed prey whole, some of the good size because the jawbones were not fixed.

 

snake without leg

4. Snake movement type

You surely distinguish the snake-like everyone else by its shape. Its body has lengthened and its limbs have disappeared to give way to a straight body, all thanks to evolution. As you can imagine it is a major change that has completely modified the biology of this reptile. The spinal column of snakes presents several characteristics related to apodic locomotion. Unlike us humans (32 vertebrae), their spinal column can reach a length of 400 vertebrae, allowing for unequaled flexibility. Second, snakes have additional processes on the vertebrae, which improves the connections between them and increases the stability of the spine, we will talk about locomotion snakes.

Rectilinear movement

This locomotion is really not complex (straight line when snake extend), it is a simple movement allowing the snake to move in a straight line. This technique consists in hanging the scales on the skin from the belly to the ground to allow the muscle composing the snake to push in the other direction and allow the reptile to advance, then it is enough to repeat this sequence. We have several species practicing this type of movement: the big pythons, boas, and vipers. This rectilinear locomotion can be summed up as an alternation between a contraction and a relaxation of the muscles ➡️, especially when they crawl towards a prey on open ground. The advantage of this practice is its slowness and therefore its efficiency with regard to prey, in other words very difficult to detect.

Lateral corrugation

This is the most common mode of transportation (sidewinder snake). The snake uses a point of contact with the ground as a support. It then lifts the trunk above the ground to establish another point of contact. This technique, however, is much faster and easier to detect. This lateral movement can be summarized by small jumps made by the snake to allow its body to move forward.

Accordion movement

In a short space, the snake contracts its muscles at the back when it extends its front part, then at the front to bring back the back. This technique is connected to an accordion because when pulling the back part of the snake, the shape of the reptile resembles the accordion 🎵. The movement can therefore be summarized in a double muscular contraction alternating the back and the front of the snake's body.

 

snake accordion mouvement

 

Now you know how snakes advance and move to attack prey. After all, evolution has done the trick. It's a bit like the human who was supposedly a monkey and then had to adapt to the situation in question to evolve and survive. It's all about the survival of the species. If you have arrived at this part of the text it is because you are a real fan of these magnificent snakes 🐍. So hurry to discover all our collections dedicated to this magnificent species. You have snake rings or even snake T-shirts.

Summary:

In order to understand the species at present, it is necessary to understand their history but above all their ancestors. For this, we can thank our scientists who work every day to make us discover more and more about the past of our planet 🌍. After our research, we can conclude that evolution has done a good job of adapting its magnificent animals. Certainly, at first sight, it seems negative because we humans can't imagine ourselves without legs. Yes, natural selection does it well. All about serpentine locomotion and snake mouvement. All these species respect the types of movement we have described: Coral-snake, Cobra, Diamondback-rattlesnake, Timber rattlesnake, Eastern diamondback rattlesnake, Reticulated python,Northern water snake, Western diamondback rattlesnake, Green anaconda, Massasauga rattlesnake. 

 


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