No, snakes don’t have legs. This is probably the most distinctive feature (or lack thereof) in snakes. But why do they not have legs?
It’s understandable why worms don’t have legs. Many of them are larvae, so they develop legs later down the line, while others are born burrowers and don’t need legs.
But snakes don’t fit any category. More importantly, many snake species are excellent climbers as part of arboreal species which, you’d think, require some appendices for grabbing stuff and providing traction.
This makes snakes seem paradoxical animals, especially when you think that many of them can move extremely fast on land.
So, let’s get into it!
Why Do Snakes Don’t Have Legs?
Why snakes don’t have legs today is still a matter of debate, but one thing is clear: snakes’ common ancestor did have legs. It is still unclear why snakes lost them, but the main theory is that the snakes’ smooth and legless bodies are the result of anatomical adaptation to hunting.
Snakes have evolved over millions of years to target prey like small mammals, reptiles, and birds that can enter tight spaces, including burrows.
Legged creatures have difficulties pursuing the smaller animals through such tight spaces, so snakes had to adapt. The lack of limbs allowed the snake to become more proficient at hunting, providing the reptile with increased agility, flexibility, and even speed.
Despite lacking legs, snakes possess extreme movement precision and graciousness, allowing them to approach their prey undetected. Their long and slithery bodies have become their main hunting tool, whether the snake is venomous or not.
This anatomical transformation has allowed snakes to occupy a unique place in their ecosystem that no other animal can steal from them.
This is why snakes are so vital for their natural habitat, most of them hunting animals and insects that qualify as pests for us.
Vestigial Leg Bones in Snakes
Snakes possess vestigial bones that are often visible to the naked eye. You can observe the residual limbs in the snake’s anal region, where the tail begins.
These look like two small fang-like structures called pelvic spurs. They’re usually located on each side of the cloaca and are larger in some species than others.
But the best way to observe the snake’s vestigial legs is during an X-ray. This allows you to view the entire internal limb structure still attached to the snake’s skeleton. This shows that snakes still have the ‘leg gene,’ just as chickens still retain their ‘teeth gene’ to this day.
As an interesting point here, the fact that snakes no longer have legs today doesn’t mean that they can’t grow them back at some point in the future. Just as chickens, who have evolved from reptiles, can lose their beaks and regrow their teeth (by the way, studies have shown that chickens can grow teeth via gene altering.)
This goes to show that evolution is a never-ending phenomenon and that nothing is ever lost but only set aside for the time being until the time is right for that particular feature again.
Snakes’ Ability to Move
So, if snakes lack limbs, how exactly do they move so efficiently and with so much precision and grace?
When it comes to locomotion, snakes can do pretty much everything and actually exhibit a mind-blowingly complex movement system.
Here are some examples to open your mind a bit:
- Lateral undulation – This is the most common movement pattern, also known as a sinuous or serpentine movement. It’s a reptile-specific locomotion relying on the snake wiggling its body side to side to facilitate forward movement. This is possible thanks to the interconnected system of muscles, bones, and ligaments, allowing the entire body to move as a whole.
- Concertina movement – Many snake species exhibit this motion movement when squeezing through tight spaces like holes and burrows. The snake pushes its body forward through the opening, then activates its muscles to drag the rest of the body behind. The result is a concertina-like movement where the body folds and unfolds repeatedly, creating visible skin folds and wrinkles.
- Rectilinear movement – Some snakes cannot exhibit lateral undulation, so they rely on rectilinear movement instead. This is similar to how caterpillars move. Boas and pythons are 2 of the several snake species that exhibit this type of movement. Rectilinear locomotion isn’t as effective as lateral undulation, but it gets the job done, allowing the snake to traverse its habitat at a reasonable pace. After all, boas and pythons are ambush predators who don’t let go of their prey once caught. So, they don’t need special movement abilities since they’re rarely in hot pursuit.
- Rectilinear undulation – This method combines lateral undulation with the rectilinear movement pattern to produce a unique movement method. The snake using rectilinear undulation moves in a straight path rather than in a zig-zag shape. It’s unclear why some snake species rely on this type of locomotion, but one suggestion is that it protects the snake from airborne predators. Birds of prey have learned to recognize snakes by their lateral movement, so a snake moving in a straight pattern may seem more innocuous.
Aside from these standard movement classifications, snakes can also do pretty much everything that other animals can do.
This includes moving at high speeds on the ground, climbing trees and rocks, swimming and remaining submerged for extended periods, and even jumping to hunt and avoid predation.
All these abilities are spread out among different snake species, depending on their evolutionary path and adaptation to their respective ecosystems.
Advantages of Snakes Not Having Legs
So, are there advantages to snakes not having legs? Or the absence of legs is rather detrimental?
Believe it or not, there are actually a handful of advantages to snakes not having legs, including:
- Improved hunting abilities – The lack of legs allows snakes to close the distance to their prey silently. The snake will make less noise and remain closer to the ground, decreasing its profile as it approaches the prey. This stays true for both venomous and non-venomous species, whether they are active or ambush hunters.
- Faster and more precise terrain traversal – The lack of legs actually allows snakes to move faster and more precise on rugged terrain. This may sound counterintuitive, but it actually makes sense. Snakes have thick underbellies covered by shiny and equally thick scales. These allow the snake to slide across rugged terrain made of sharp rocks or other rough materials, seemingly, with little effort.
- Increase in size – The absence of legs allowed snakes to grow larger, which improved their survivability and hunting abilities. This may sound awkward until you realize that the brain is in charge of the whole body as a complete system. A legged snake would force the brain to divert energy and resources toward limb maintenance, a feature that is no longer necessary in modern snakes. This means that the brain can use that energy to expand the snake’s body, making it more adept at hunting and decreasing the number of natural predators that could kill it.
- Better energy management – Snakes may not reach the land speeds of legged creatures, but they can certainly take longer journeys thanks to their improved energy management. Part of this is thanks to their lack of limbs, which would have increased their energy expenditure.
This being said, things are not all perfectly wired up. This means that there are also disadvantages to the snakes’ evolutionary path, so let’s look into those as well.
Disadvantages of Snakes Not Having Legs
Unfortunately, there are several disadvantages to lacking limbs for locomotion. If there weren’t, nobody would’ve had any legs, to begin with.
The main downsides include:
- Limited mobility on rugged terrain – This may sound like a contradictory point, given that I’ve already explained how the lack of limbs provide snakes with smoother and more precise movement on rugged terrain. What matters, though, is the difference in ruggedness, if you will. Snakes have no problems moving fast on uneven terrain, but they have problems traversing areas with larger rocks, tree trunks, bushes, and other types of elements. A legged animal would simply hop over everything, whereas snakes don’t have that luxury.
- Limited defensive capabilities – Snakes can flee from their predators, but they have limited ability in this sense. They’re unlikely to outrun their main predators because legged creatures are simply faster and more agile. The lack of limbs also means that snakes don’t have claws to defend themselves. This is the main reason why the snakes’ primary defensive mechanisms include camouflage, staying still, playing dead, or exhibiting intimidation behaviors like inflating the body, hissing, etc.
- Difficulties climbing – Many snake species are excellent climbers, but they’re not equally proficient in all situations. Snakes have difficulties climbing vertical objects like rocks or abrupt trees, so they have to be picky about their climbing spot. They also can’t traverse their arboreal habitat with ease, which limits their defensive capabilities significantly.
- Limited hunting abilities – Snakes rely on camouflage and ambush-like behaviors for a reason. They simply cannot tackle their prey head-on or chase it actively (although some species can do that) simply because most animals are faster than them. So, they need to rely on finding a vantage point and waiting for the prey to wander close by.
Even with all these downsides, snakes have evolved into astounding predators, capable of consuming nearly anything so long as they can swallow it.
Conclusion
The fact that snakes don’t have legs today is an indicator that they don’t need them. They do just fine without limbs and have adapted other physical and behavioral characteristics to make up for their absence.
This being said, snakes have the genetic code for legs, and it’s not unreasonable to think that they will grow them back when their ecosystem requires them to.
