Lizards and snakes may seem closely related, but they are actually quite different reptiles. However, there are some lizard species that closely resemble snakes in appearance. These legged lizards lack visible ears and have long, cylindrical bodies without obvious limbs.
If you come across one, it can be tricky to discern whether you’re looking at an unusual snake or a snake-like lizard.
If you’re short on time, here’s a quick answer to your question: There are several lizard species, such as glass lizards and slow worms, that have evolved to resemble snakes with small legs or reduced limbs.
In this comprehensive guide, we’ll cover the key characteristics, features, and examples of lizards that look strikingly snake-like. We’ll discuss their anatomy, behaviors, habitat, distribution, and how to tell them apart from actual snakes.
Read on to learn all about these fascinating legged reptiles that have adapted to fill a serpentine niche.
Anatomy and Physical Features
Elongated bodies
Many lizards that resemble snakes have evolved extremely elongated bodies, with their trunks making up 50-80% of their total length (Reeder et al. 2015). For example, the Eastern glass lizard (Ophisaurus ventralis) has an average snout-to-vent length of 20 inches, with an additional 16 inch long tail (Beane et al.
2010). This streamlined profile aids these legless lizards in smoothly gliding through their habitats. It also makes them superficially look like small snakes.
Reduced or absent limbs
While over 97% of lizard species have well-developed limbs, several lineages exhibit the evolutionary loss of legs (Wiens et al. 2006). Legless lizards leverage the muscular contractions of their spine and belly scales to propel themselves forward instead.
Species like the European glass lizard (Pseudopus apodus) retain tiny vestigial hind limbs buried under the skin. But many other legless lizards lack any external traces of limbs altogether.
Lack of visible ear openings
Snakes don’t have any external ear structures. Similarly, ear openings are also absent or difficult to discern in some snake-mimicking lizards. For example, Scheltopusik (Pseudopus apodus) vestigial ears are entirely covered by scales (Arnold 2002).
This feature adds to their serpentine facade, which likely helps avoid detection by predators.
Smooth scales
Instead of the rough, granular scales seen in other lizards, snake-like species tend to have small cycloid scales that lie flat. Researchers believe this difference helps reduce friction and aids their movement through ground vegetation (Arnold 2002).
The smooth scales also enhance their resemblance to snakes upon casual inspection.
Behavior and Movement
Serpentine movement
Many lizards that resemble snakes share the unique ability to move in a wavy, side-to-side pattern similar to serpents. Species such as the scheltopusik (Ophisaurus apodus) and European glass lizard (Pseudopus apodus) lack limbs or have severely reduced limbs and employ lateral undulation to propel themselves.
This is accomplished by contracting muscles on one side of the body while extending those on the opposite side, enabling sinuous movement. Such serpentine locomotion allows limbless lizards to navigate terrain and move through vegetation and narrow spaces with ease.
Burrowing habits
While snake-like lizards tend to inhabit terrestrial settings, some demonstrate impressive burrowing capabilities. The slow worm or blindworm (Anguis fragilis), for instance, is covered by smooth scales that facilitate subsurface travel.
It tunnels just below the surface searching for its main prey – earthworms and insect larvae. Similarly, the European legless lizard (Chalcides chalcides) sports a streamlined build for burrowing through sandy soil environments around the Mediterranean region.
Its shovel-shaped head is a highly adapted tool for such endeavors. Clearly, select limbless and leg-reduced species have evolved excellent fossorial talents enabling life largely below ground.
Primarily terrestrial
Overwhelmingly, snakes and snake-like lizards are land dwellers. While serpents such as sea snakes and water moccasins have adapted to aquatic habitats, these are exceptions. Legless lizard species like the slow worm and European glass lizard, together with those having reduced appendages like Bipes biporus (five-toed worm lizard), are fully terrestrial.
They may take refuge underground or rely on dense vegetation, but are otherwise bound to the ground. Even the aptly named Flying Dragon (Draco volans) only appears airborne briefly, thanks to patagial membranes between its limbs that function more for display than sustained flight.
So while some have shifted to novel domains, most keep to solid earth, where undulatory locomotion and burrowing allow them to thrive as limbless ground dwellers.
Habitat and Geographic Range
Lizards that resemble snakes with legs are found worldwide, except for the icy continent of Antarctica. These fascinating creatures thrive in diverse habitats ranging from sandy deserts to tropical rainforests.
Their ability to adapt has enabled them to spread to all corners of the globe, apart from the freezing south polar region.
Found worldwide except Antarctica
The snake-like lizards have managed to colonize all continents except Antarctica. With over 3,800 known species, they have adapted to live in a wide range of ecosystems. From the scorching Sahara desert to the lush Amazon rainforest, you can find these legged reptiles slithering around.
Their absence in Antarctica is unsurprising, given the frigid temperatures and lack of vegetation.
Prefer tropical to temperate regions
Although found globally, most species prefer tropical and subtropical climates. The warm weather, abundant prey, and vegetation make these regions ideal habitats. For example, Indonesia’s Komodo dragons thrive on the sunny islands filled with prey.
Temperate areas like North America and Europe have fewer legged lizard species. Colder regions provide challenges like hibernation and scarcity of food.
Fossorial species live underground
Some lizards have adapted to subsurface life. These fossorial species spend most of their time underground, only surfacing occasionally. Their shovel-shaped heads and reduced eyes aid their burrowing lifestyle.
Living underground provides advantages like stable temperatures, humidity, and protection from predators. Examples of these lizards are the Mexican mole lizard and the spider-tailed horned viper found in Iran.
Examples of Snake-like Lizards
Glass lizards
Glass lizards belong to the genus Ophisaurus and look incredibly similar to snakes, despite actually being a type of legless lizard. They have long, slender bodies that can grow up to 4 feet in length. Their skin is smooth and shiny, often leading people to confuse them for snakes.
However, upon closer inspection, glass lizards have noticeable differences. They have movable eyelids, while snakes do not. Glass lizards also have external ear openings, which snakes lack. Additionally, the scales on glass lizards overlap one another, unlike the individual scales of snakes.
When threatened, glass lizards can voluntarily detach their tails. The detached tail will then writhe on the ground, distracting predators while the lizard makes its escape. How cool is that?
Slow worms
Slow worms, also called blindworms, comprise the Anguis genus of legless lizards. Despite the name “slow worm,” they can actually move quite quickly. These lizards are found throughout Europe and resemble snakes with their limbless bodies that can reach up to 16 inches in length.
However, slow worms have several features that distinguish them from snakes. They have movable eyelids, ear openings, and a tongue that is not forked. While snakes rely on venom to subdue prey, slow worms grab prey with their jaws and teeth.
They are also physically unable to unhinge their jaws like snakes. An interesting fact about slow worms is that they are viviparous; the mothers give birth to live young rather than laying eggs.
Legless lizards
There are over 200 species of legless lizards around the world, predominantly in desert environments. For example, the California legless lizard is found in the southwestern United States and northern Mexico. Legless lizards lack legs or have vestigial legs, giving them a snake-like appearance.
However, they have eyelids, ear openings, and a tongue that is not forked like snakes. Many legless lizard species also have visible vestiges of their limbs buried under their skin. Unlike snakes, they cannot unhinge their jaws to consume large prey.
While some legless lizards prey on insects and spiders, others may feed on vegetation. Legless lizards are amazing reptiles that have adapted to life without limbs!
Sheltopusik
The sheltopusik is a fascinating legless lizard found in Asia and Europe. With its limbless, cylindrical body, it resembles a snake but is actually a lizard. Sheltopusiks can grow over 3 feet long. They have movable eyelids, ear openings, and a non-forked tongue that snakes lack.
Their scales are small and granular compared to the larger, smooth scales of snakes. Sheltopusiks are skilled climbers and often climb into bushes and low branches of trees. Their prehensile tail helps anchor them as they climb.
Sheltopusiks consume insects, spiders, smaller reptiles, eggs, and small mammals. When threatened, they may thrash their body and strike in defense. However, they are not venomous like some snakes. The sheltopusik demonstrates how legless lizards have adapted snake-like features to thrive in their environments.
Distinguishing Snake-like Lizards from Snakes
Vestigial legs
Many lizards that resemble snakes still retain tiny vestigial legs, complete with feet, toes, and claws. These reduced legs are completely absent in true snakes. Vestigial legs may appear as small flaps of skin on each side of the body near the vent.
Though nonfunctional for walking, they provide evidence that these legless reptiles evolved from lizard ancestors.
Eyelids
Snakes lack movable eyelids and instead have a clear scale called a brille that permanently covers their eyes. Legless lizards, on the other hand, have eyelids like other lizards that can open and close to moisten and protect their eyes.
Observing whether the eyes have brilles or movable eyelids can help distinguish snakes from legless lizards.
Facial scales differ
The scales on a snake’s head are very similar in size and shape to the scales along the rest of its body. Legless lizards, however, have noticeably larger, plate-like scales on the top of their head. These shield-shaped head scales, called cephalic plates, are an important feature used to identify legless lizard species.
Tail shape
Most legless lizards can voluntarily shed their tails as a defense mechanism, so tail shape varies greatly within a single species. However, some general trends can help differentiate lizard tails from snake tails.
Lizards tend to have shorter, thicker tails, while snake tails are longer and more slender. A snake’s tail also tapers smoothly to a point, whereas a lizard’s tail often appears truncated after tail loss and regeneration.
Conclusion
Lizards that resemble snakes have evolved special adaptations like limbless or reduced limbs and elongated bodies to thrive in ground-dwelling niches. While they mimic serpents, key anatomical features like eyelids, vestigial leg structures, and scale patterns can help distinguish them.
These legged reptiles fill an important ecological role in many habitats around the world. Though they may startle some observers on first glance, snake-like lizards are harmless and fascinating to learn about.
