To begin with, lizards are reptiles. Like all reptiles, they share the following features: .
They are vertebrates. .
They have dry, scaly skin. .
They are cold-blooded,… or 'ectothermic', meaning they cannot generate their own heat to maintain body temperature, but instead have a variable body temperature which reflects the animal's environment. .
They breathe using lungs (unlike fish or juvenile amphibians). Lizards also have more specific features in common: .
Lizards generally have four well-developed limbs with five toes each. This does not include legless lizards which move like snakes, and burrowing lizards, which have less well-developed limbs. .
Most lizards, unlike snakes, have movable eyelids. .
Lizards have a three-chambered heart. .
Lizards have a pineal body which is connected to a "third eye." The "third eye" is invisible in most species, but it is a light-sensitive transparent disk on top of the head which is believed to regulate a lizard's "biological clock". .
Many species have effective camouflage, being able to change their colouring slightly so as to be less obvious in their surroundings. .
Many species are also able to drop their tails without any effect on the lizard. This is an effective defence against predators. (MORE)