Are snakes reptiles? Despite their different body structure, snakes share all of the necessary physiological traits that make up the reptile group. These include both their external structure (e.g., their skin) and their internal structure (e.g., their bones and organs). Snakes even share the more interesting facets of reptiles, such as being venomous.
Why Snakes are Classified as Reptiles
Perhaps the two most distinct features of snakes are their lack of limbs and scaled body. Regarding their lack of limbs, snakes are still considered reptiles because there are descended from tetrapods (e.g., animals that had four limbs). Additionally, some snakes still retain legs in the form of pelvic spurs, including boas and pythons. These spurs are purportedly the vestigial remains of limbs and still have bony cores.
Snakes are also firmly classified as reptiles because of their skin. All reptiles have non-glandular skin with either scales or scutes, a type of bony plate. Both scales and scutes are made of keratin, the same protein present in human nails.
Reptiles in general are incredibly diverse and include animals such as turtles, lizards, crocodiles, tuataras, and more. But across this ecological abundance there are some absolute similarities. For example, all reptiles are ectothermic (e.g., cold-blooded) vertebrates that use their lungs for respiration. All three characteristics are present in snakes. Additional similarities are laid out in the next section, such as their typical habitats and defense mechanisms.
Similarities Between Snakes and Other Reptiles
Snakes, like reptiles, are classified as herpetofauna and are one of the animals referred to as herps. As noted earlier, snakes and other reptiles are all ectothermic, which means they are cold-blooded and unable to regulate their body temperature. They use their environment to warm up or cool down as needed to remain stable. As a result, nearly all snakes and other reptiles thrive in warm or hot environments, regardless of whether the environment is wet or dry.
Snakes are one of the most popular pet reptiles. So if you keep a snake as a pet, heat elements will therefore be crucial. Heaters for water and heat lamps for land are essential for any enclosure. You’ll also need a thermostat to make sure the enclosure is the appropriate temperature. Using these tools, you can establish a temperature gradient with hot and “cold” (re: less hot) sides for body regulation.
Temperature also plays into why snakes are classified as reptiles: most lay amniotic eggs. These eggs are internally fertilized and then the snakes lay eggs that hatch later on (e.g., oviparity). Snake eggs (and the eggs of other reptiles) undergo temperature-dependent sex determination. This means that the environmental temperature during early stages of embryonic development impacts whether the reptile will be male or female.
An additional similarity is that several types of reptiles (snakes included) use toxins as a defense mechanism. Some snakes are venomous, such as cobras and vipers, though it can be difficult to identify a venomous vs. non-venomous snake. Other dangerous reptiles include the Gila monster, Mexican bearded lizard, and Komodo dragon. Technically, iguanas are also venomous, although their venom glands have atrophied to the point that the venom itself is harmless.
Differences Between Snakes and Other Reptiles
Perhaps the most obvious difference between snakes and other reptiles is the fact that snakes are legless. Even those with pelvic spurs are still technically (and functionally) limbless. Despite this, snakes are still very active. Like other reptiles, snakes can still climb, swim, and move quickly. Snakes actually move in a number of different ways, including lateral undulation, side-winding, concertina, and rectilinear.
Another difference between snakes and other reptiles is that most reptiles are egg-laying. And while the majority of snakes also reproduce via oviparity, some species can also reproduce via viviparity. With viviparity, snakes develop the offspring inside themselves initially and then give birth to live young. Sea snakes are one example of snakes that give birth to live young.
Similarities and Differences Between Snakes and Caecilians
Snakes are unique amongst reptiles because they are limbless. And just as there are many similarities between reptiles and amphibians, so too do amphibians have a limbless member: caecilians. Caecilians are limbless, often eyeless amphibians that are typically described as serpentine.
There are a number of similarities between snakes and caecilians beyond their lack of legs, however. Like snakes, caecilians prefer humid and tropical environments. And, also like snakes, caecilians can also be fossorial, terrestrial, semi-terrestrial, or even aquatic. Another similarity is the fact that some species of caecilians bear live young, while others are egg-bearers.
Unlike snakes, most caecilians are blind and either do not have eyes or have very small eyes. Some species of caecilians even have skin that grows over their eyes, effectively rendering them eyeless. This makes sense from an evolutionary perspective however: although caecilians can be found in a variety of habitats, they are primarily fossorial.
Another difference is the way in which caecilians develop. Like other amphibians, caecilians do go through a metamorphosis as they mature. Caecilians are born with gills and eventually transition to using lungs for their respiration. And their skin, which is glandular (unlike snakes), can also be used for cutaneous respiration.
