What is a lizard? Lizards are part of a group of animals known as reptiles. They are most closely related to snakes. In fact, some lizards, called sheltopusiks, look like snakes because they have no legs! Many lizards today resemble the ancient reptiles of the dinosaur era. Their ancestors appeared on Earth over 200 million years ago.
In general, lizards have a small head, short neck, and long body and tail. Unlike snakes, most lizards have moveable eyelids. There are currently over 4,675 lizardspecies, including iguanas, chameleons, geckos, Gila monsters, monitors, and skinks.
Most lizards have eyelids, just like we do, that clean and protect their eyes when they blink. But some lizards, like geckos, can’t blink! Instead, they have a clear membrane that shields their eyes from dirt or bright sun and use their tongue to clean their eyes. Many lizards, such as iguanas, can see in color. Their colorful body parts allow them to communicate with each other and help them tell which are male and which are female.
Lizards smell stuff with their tongues! Just like snakes, a lizard sticks out its tongue to catch scent particles in the air and then pulls back its tongue and places those particles on the roof of its mouth, where there are special sensory cells. The lizard can use these scent “clues” to find food or a mate or to detect enemies.
Lizards don’t have earflaps like mammals do. Instead, they have visible ear openings to catch sound, and their eardrums are just below the surface of their skin. Even so, lizards can’t hear as well as we do, but their hearing is better than that of snakes.
Lizards have dry, scaly skin that does not grow with their bodies. Instead, most lizards shed, ormolt, their old skin in large flakes to make way for the new skin growth underneath. The exception to this is with the alligator lizard, which may shed its skin in one piece, like a snake. The scales on lizards vary, depending on their habitat. Skinks have smooth scales so mud won’t cling to them; some lizard species have bony plates, called osteoderms, under their scales for added protection against rough terrain.
Lizards are popularpreyfor many types of predators, from birds of prey to snakes and carnivorous mammals. Theircamouflageand ability to stay still for hours helps keep them safe. Several types of lizards are able to escape from an enemy’s grasp by breaking off part of their own tail. The tail has a weak spot just for this purpose. If apredatorgrabs the lizard by its tail, the tail easily comes off. It can grow back over time, although the tail won’t look quite the same. Still, it’s better than being someone else’s dinner!
Other lizards have different ways to stay safe. Horned lizards are able to squirt blood from tiny blood vessels in their eyes to scare away or confuse a predator. The armadillo lizard has sharp, spiky scales and can roll up into a tight ball to protect its soft belly from attack. The sungazer lizard has impressive spikes that cover its body, including the tail. The alligator lizard bites, thrashes about to get loose, or voids foul-smellingfeces. The tropical girdled lizard darts into a crack, expands its body, and lodges itself in so tightly that a predator can’t remove it.
The shingle-backed skink is the reptile equivalent of Dr. Doolittle’s two-headed llama, the “push-me-pull-you” with its fat, wide tail that resembles the head. If confronted by a predator, the skink bends its body into a C shape, which confuses the predator because it appears as if the skink has two heads. The Australian frilled lizard has a “frill” of loose skin around its neck that can stick out when the lizard is frightened. This makes the lizard look much bigger than it really is, and a predator may decide to look for something smaller to eat. If that doesn’t work, the lizard runs away on its hind feet!
