Lizards are tetrapod (four-legged) animals that belong to the Reptilia class in phylum Chordata. Phylum Chordata is one of the many phyla in the animal kingdom (Kingdom Animalia).
Over 6,000 species of lizards exist in the world. They vary in terms of size, weight, appearance, color, behavior, and in many other aspects.
Are Lizards Reptiles or Amphibians?
Lizards are reptiles. While reptiles do share some similarities with amphibians, the two groups of animals are also significantly different.
Examples of reptiles include lizards, skinks, geckos, snakes, crocodiles, alligators, chameleons, and turtles. While examples of amphibians include frogs, newts, and salamanders. From these two groups of examples, I am sure you can clearly see that reptiles/ lizards are quite different from amphibians.
In the next section, I will share with the similarities between lizards and amphibians. It is the similarities between lizards and amphibians that make some people confuse lizards for amphibians.
So What Are The Similarities Between Lizards And Amphibians?
Many people confuse lizards for amphibians because lizards share several similarities with amphibians. Below are the similarities between lizards (reptiles) and amphibians.
- Both lizards and amphibians are cold-blooded
- Both lizards and amphibians belong to phylum Chordata (have a backbone)
- Both lizards and amphibians alter their skin color
- Both lizards and amphibians have got good eyesight
- Both lizards and amphibians have got varying defensive responses
As you can see above, lizards share many similarities with amphibians. This is why it is easy for some people to wrongly assume that they belong to the amphibian group. Lizards are not amphibians. They do share many similarities with amphibians but they are also vastly different from amphibians as you will see below.
So What Are the Differences Between Lizards and Amphibians?
As stated earlier in this post, lizards are reptiles. They are classified as reptiles because they look and behave like reptiles and they are significantly different from amphibians. Below are the key differences between lizards and amphibians.
- Lizards, like most reptiles, exclusively breathe through the lungs. In contrast, most amphibians including frogs, salamanders, and newts can breathe through the lungs and through their skin.
- Lizards, like all reptiles, have got several neck vertebra. This allows them to move/ twist their heads significantly. In contrast, amphibians have got only one neck vertebra so they cannot move their heads much.
- Lizards have got dry and scaly skins like most reptiles. Their skins protect them against water loss. This is the reason why they can leave in many different habitats. In contrast, amphibians mostly have smooth and moist skin that does not really protect them against water loss. This is the reason why they must live close to a constant water body.
- Lizards, like most reptiles, lay their eggs primarily on land. In contrast, all amphibians lay their eggs in damp media.
- Lizards, like all reptiles, do not undergo metamorphosis. In contrast, all amphibians undergo metamorphosis.
- Lizards, like most reptiles, have got an organ known as Jacobson’s organ located in the roof of their mouths that allows them to locate prey, predators, and mating partners easily. In contrast, amphibians do not have this organ. They use other mechanisms.
As you can see from the points above, lizards are much more like reptiles and very different from amphibians despite having some similarities with them (amphibians). Because lizards share more similarities with reptiles and are significantly different from amphibians in some ways, they are classified as reptiles. If it looks like a duck, swims like a duck, and quacks like a duck, then it is a duck. In this case, the points above prove that lizards look like reptiles, live like reptiles, and do everything like reptiles. So they cannot be anything else other than reptiles.
So now you know why lizards are reptiles and that they are too different from amphibians to be classified or grouped as amphibians.
Frequently Asked Questions about Lizards
How Many Species of Lizards Exist?
There are over 6,000 species of lizards known to man. The many species vary in terms of size, shape, appearance, body systems, capabilities, and so on. Examples of lizard species include skinks, monitor lizards, Gila monsters, geckos, chameleons, and iguanas. Chameleons and iguanas are quite different in appearance from other lizards that people assume they are not lizards but they are.
Where Are Lizards Found?
Are Lizards Social or Solitary Animals?
Most lizards are solitary animals. They prefer doing things solo. However, many lizards are social and like living in numbers.
What is the Smallest Lizard and what is the largest Lizard?
The smallest lizard known to man is the dwarf gecko. It measures just 1.6 cm when fully grown so it is a very tiny gecko/ lizard. It lives in the United States Virgin Islands. While the largest lizard known to man is the Komodo dragon.
The Komodo dragon can grow as long as 10 feet in length and it can weigh up to three hundred pounds. In short, it is a massive animal by most measures. It is so big that it can take on and kill a water buffalo. The lizard is only found on the Indonesian islands of Gili Dasam, Gili Montang, Komodo and Rinca.
Do Lizards See Color?
Most lizards do not see color. In other words, they do not like you and me. Therefore, colors do not mean much to lizards. They usually use their sight and other senses to go about their lives. For example, many lizards are known to sense with their tongues like snakes and this helps them to find and follow clues to hide from predators and prey or to find mates.
Some lizards, however, do see color. They see colors and use colors to talk with one another especially during the mating season when the need to communicate is very high. The most common lizard that can see color is the iguana.
Are Lizards Venomous?
No, they are not. Nearly 100% of all the lizards known to man are not venomous. Only two lizards are known to be venomous to man and they are the Mexican bearded lizard and the Gila monster.
What Foods Do Lizards Like?
Different lizard species like different foods. Some are insectivorous/ carnivorous, some are herbivorous, and some are omnivorous. Insectivorous/ carnivorous lizards are those that eat prey such as insects and small animals. Herbivorous lizards are those that strictly eat plant matter and omnivorous lizards are those that eat everything.
Captive lizards are known to prefer eating grasshoppers, ants, flies, crickets, flowers, fruits, and leaves.
The best known herbivorous lizards are iguanas.
Why Do Lizards Bask in The Sun?
Lizards like basking in the sun because they are cold-blooded animals. So they bask in the sun to warm up after spending hours in the cold earth or elsewhere. What I am trying to say is that lizards that bask do so to regulate their temperature and to avoid freezing.
Because lizards do not generate their own heat like warm-blooded animals, they need the sun. For this reason, if you want to keep a lizard pet, you should buy a basking platform and a heating lamp. This is because your lizard tank/ enclosure is obviously going to be inside your house and since the sun’s heat will not reach your lizard, you will need to recreate it by having a heat lamp over your tank.
If you do get a heat lamp your lizard will probably die sooner rather than later.
Can Lizards Walk On Water?
No, lizards cannot walk on water. However, one lizard species – the Jesus Christ Lizard – can walk and can run on top of water. The lizard, also known as the basilisk lizard – is commonly found in the rainforests and streams of South and Central America.
Most Lizards have a Secret “Third Eye”?
Most lizards have got a series of nerves on their forehead that enable them to know direction like some sort of natural GPS.
Lizards are definitely reptiles. They look like reptiles, walk like reptiles, and have reptilian features. So they can be nothing else other than reptiles. They do have some similarities with amphibians but they are also significantly different from amphibians. So they are reptiles and that is what they have been since the classifications of animals started being included in biology texts.