How Do Snakes Move Without Paws?
What happened during the evolution that snakes lost their legs? Or except for a few, why don’t snakes move in a straight line? How can a snake swim without limbs? Do snakes crawl or slither? How can snake move without paws?
I am author James Adams, a member of the research team dedicated to behavioral sciences of snake species. I am also a correspondent writer for the Snake Store Team. As a snake owner and narrative research reporter on snakes evolutionary biology, I want to share one of the most fascinating aspects of serpents with you here; the mechanism of snakes’ movements.
As a limp-less reptile, snakes move by using their bodily muscles with Rectilinear locomotion. Additionally, they use their scales to cling against ground and other objects to assist their movements. While some parts of the body remain motionless, others force the body forward or in other directions.
This article takes you on an informational journey through the following subtopics;
- A glance on snake movement in variety of species
- An abstract on the physical evolution of snakes and loss of their limbs
- Theories on historic evolution of serpents from the ancestors until present-day species
- Variety of movements assisting snake’s in different environments
Read on to discover the scientific secrets of snake’s appearance and their movements;
Snakes can move by crawling on the ground, thanks to their muscles. So, evolution has succeeded in its jobs, as the species of snakes don't need paws anymore. That's why the snake crawls, it doesn't walk. It bends and pushes with the back of its body and then unfolds. The snake then brings his tail back towards his head and repeats the same sequence of movements. Similar to a belly dance, the snake knows how to move its belly skin to move forward.
We will not discuss poison, venom (toxin), or antidotes, but movement... to live and survive. Fishes swim, hawks soar through the sky, moles dig tunnels, and squirrels jump to breed, scavenge, or escape predators. Coordination of complex biophysical processes handle these feats of locomotion, at the molecular scale (molecules control the propagation of information in neurons), at the intermediate scale (muscles and tendons coupled with skeletal elements drive the movement of different body parts), and at the large scale (certain parts of the body, including feet and hands, interact with their environment to move forward). One goal of locomotion science is to discover general movement principles through the development of multi-scale models. This challenge requires collaboration between biologists, physicists, mathematicians, and engineers. Their research studies inspire the vehicle design involving mobility equal to or exceeding that of animals.
Snake bodies differ between snake species, and they lack legs and arms. Their agile can squeeze through incredibly narrow places. How do they do this? Snake bodies comprise a combination of flexibility in the spine (vertebrates), a strong musculature, and their ventral scales at the bottom. An adult human spine has 26 vertebrae, while snakes have over 400, which means they have far superior truck movement compared to humans. Every pair of snake ribs is attached to one vertebra.
When a snake moves, the posterior parts of the scales grip the surface and attach themselves to the ground, making an opposite movement to the muscles and driving them forward (anterior part). A snake's movement depends on the land they are currently on. This provides a beautiful example of adaptation, which illustrates the snake's strength and flexibility to adapt to any terrain. The horned rattlesnake with its survival tricks in sandy habitats where it lives is an excellent example of adaptation. Its movement involves moving forward and sideways, with its lower body and tail raised above the hot desert sand. This leaves a J-shaped pattern which can be scary to see.
The Emerald tree boa is a snake that can climb trees. This species wraps itself around a tree and then slides gently like an accordion. As it extends its head forward, its tail helps it cling to the tree trunk, taking the momentum to push its body along.
1- Why don't snakes have legs?
Two research teams working on this question discovered that snakes were the victims of Sonic Hedgehog. This is a protein that regulates the formation of fingers and other matter during the embryonic development of mammals. Scientists already knew this protein played a decisive role in reducing the size of a lizard's legs. The Sonic Hedgehog affected the evolution of many reptile species, including the lack of legs in snakes. A University of Florida biologist, Martin Cohn, discovered that proteins had little chance to access Sonic Hedgehog during the python's embryonic stage. Without this, an animal's legs cannot develop.
Axel Visel, a Lawrence Berkeley National Laboratory researcher in California, also researched this subject and published his results around the same time as Cohn. Vise implanted the Sonic Hedgehog in mice and observed the subsequent litters' development. Normal mice possessed legs, while those with the protein had bumps. More information about this study is available on the NCBI website. While the gene is not wholly involved in the snake's mutation, it is significant in its physical evolution. Scientists have welcomed the conclusions reached by these two teams and partially answer the question, "Why don't snakes have legs?" However, researchers continue to investigate this fascinating subject.
2. How did snakes lose their paws?
A Chinese charade has you guessing who runs without legs, swims without fins, and glides without wings. The answer? The snake of course! Over 3,000 current species have a limbless body capable of moving on the ground, in the water, and the air from one tree to another. However, their oldest ancestors had limbs of various shapes and sizes, which begs the question: how did snakes lose their legs?
The specialization of limbs is often linked to their environment. For example, Whales have fins because of their ancestor's adaptation to the marine environment. Similarly, wings developed when birds started moving in the air. And snakes? Evolutionary biologists have discussed this for decades, probably due to snakes being so widespread now despite the tiny fossil record of the first snake. The debate focuses on two hypotheses: The first suggests that snakes lost their legs when adapting to marine life, while the second believes this happened when snakes started adapting to life in underground environments.
If we could transport back to the start of the snake evolution. It would be possible to observe their ancestors in their Cretaceous habitats, 145 to 66 million years ago, and determine if they excelled at swimming or digging burrows. We only have fossil remains to guide us today. It is difficult to reconstruct an animal's ecology and behavior from bones alone, especially if fossils have caused damage or fragmentation.
However, over the last ten years, advances in imaging techniques have provided further understanding of the origin of snakes. X-rays have discovered new characteristics of the snake's bone structure. Simultaneous evolutionary developmental biology research has investigated the genetic mechanisms which led to the snakes' limbs disappearing and their vertebrae multiplying. Our knowledge of the origin of snakes is far from complete, but we have a better understanding of their evolution, which to some extent has been explained by the Sonic Hedgehog gene.
The Dinilysia Patagonia is the first known legless snake, appearing some 85 million years ago (late Cretaceous) when dinosaurs still dominated the planet. Extremely well preserved, its almost complete skeleton was found in the Patagonian plateau's rust-colored sandstone. This species had no limbs, no scapula (shoulder support), or pelvic girdle comparable to that of man.
The oldest known legless reptile was larger than today's burrowing snakes. However, members were present in some snake species. The Najash Rionegrina, a terrestrial species in South America, particularly in Argentina, is estimated to be 92 million years old, is not much longer than a spaghetti. Its small hind limbs comprise bony elements from hip to ankle. Too small and delicate to support the animal's weight, they would be useful for clinging to the partner during mating instead. Other legged snakes of the Upper Cretaceous, including the Jerusalem area, fill the oceans. Marine deposits have yielded fossils of sea snakes that swam in waters inhabited by sharks. Two fossil forms, Pachyrhachis and Haasiophis, were characterized by their almost complete hind limbs comprising thigh, leg, and foot bones and their function is unknown (not everything is always known!). As the Pachyrhachis and Haasiophis' limbs were not connected to the trunk by a pelvic girdle, their legs did not assist swimming.
3- Who was Dinilysia Patagonia?
The oldest known snake, Genus Dinilysia (Terrible Destroyer), evolved from lizard ancestors approximately 85 million years ago. Living in the Upper Cretaceous, its remains were discovered in the Coniaciense of Argentina, in South America. This snake's length reached 1.8 to 3 meters and it preyed on small animals. This creature's skull shape does not support the view that snakes were originally diggers; it is clear that Dinilysia was terrestrial.
Dinilysia killed its prey by strangulation and was not poisonous, like today's boas (Boa Constrictor) and pythons. It swallowed prey whole because of its flexible jawbone.
4- Snake movements
Snakes are distinguishable, like everything else, by their shape. The lengthened body and vanished limbs have provided a straight body, thanks to evolution. The reptiles’ biology has completely changed. Characteristics of the snake's spinal column are related to apodic locomotion. Their spinal column can contain 400 vertebrae, allowing for unequaled flexibility compared to a human's 32 vertebrae. Secondly, snakes have additional vertebrae processes, which improve these interconnections and increase the spine's stability Next, we will discuss locomotion snakes.
a) Rectilinear movement
Locomotion is not complex. It refers to the snake's extension in a straight line, a simple movement allowing the snake to move in a straightforward manner. This technique involves hanging the skin scales from the belly to the ground, allowing the muscle composing the snake to push in the other direction, so the reptile can advance. This movement sequence occurs repeatedly to create the locomotion movement. Several species practice this type of movement, including big pythons, boas, and vipers. This rectilinear locomotion can be summarized as alternating between muscle contraction and relaxation, especially when crawling towards prey at ground level. Advantages of this movement include the slow speed and increased efficiency when seeking prey, as the snakes are difficult to detect.
b) Lateral corrugation
The most common mode of transportation is lateral corrugation. The Sidewinder snake uses a point of contact on the ground as support before it raises its trunk above ground to establish another point of contact. This is a much faster technique, but easier to detect. This lateral movement is characterized by small jumps made by the snake, allowing its body to move forward.
c) Accordion movement
In smaller areas, the snake contracts its back muscles while extending its front part, then brings back the back to the front. This technique is likened to an accordion because the reptile resembles the instrument when pulling the snake's back and extending the front. This movement is a double muscular contraction alternating between the back and the front of the snake's body.
You now know how snakes advance and move to attack their prey. After all, evolution has done the trick. It's like us humans were once monkeys who adapted to their habitat to evolve and survive. Survival of the species is the case at hand. If you have read this far, you must be a real fan of these amazing reptiles.
5- Aesthetics of Sinuous Movements of Snakes
While all snakes movements look alike to the untrained eyes, you are now aware that not all the snakes move the same and it is widely characterized based on species. You have also gained a wealth of knowledge on the evolution of snakes and the ecological reasons for losing the feet- which you can share for your loved ones next exam assignment or offer your valued knowledge to those who are fascinated about reptiles like yourself. You have understood that slithering is not the only trick in the bag that snakes use to move, hunt, and defend themselves; instead, they employ a variety of muscular motions to swim, jump, slither, and rise vertically.
Science aside, the sinuous fluidity of serpents is one of nature’s most impeccable beauty aesthetics. Flowy, graceful and seductive are the words associated with snakes’ movements. Check out our snake clothes collection- that not only draws inspiration from fluidity of a snake but also compliments the desirable feminine contours and highlights the bold virility of a man’s elegance.