Lizard is a common name for any of the members of the reptile family Lacertidae. The family includes about 38 genera and over 600 species. Lizards range in size from geckos, which may be no more than 6 cm (2.4 in) long, to Komodo dragons, which can reach 3 m (10 ft). Most lizards are quadrupedal, running with an upright stance. The majority of lizards have four legs and external ears, while some possess only two or none at all.
Lizards typically have dry scaly skin that helps them to regulate their body temperature by basking in the sun or hiding in shade. Many lizards also have keeled scales that give their skin a rougher texture. Some species of lizard can shed their skin periodically as a means of regeneration or defense against predators.
Lizards are found on every continent except Antarctica. They live in a wide variety of habitats including deserts, rainforests, grasslands, and forests. Some species are arboreal while others dwell underground; still others are semi-aquatic living near bodies of water such as rivers and lakes. Diet varies among lizard species and may include insects, other invertebrates, fruits, flowers, carrion, or small vertebrates such as rodents and birds.
Most lizards are oviparous meaning they lay eggs; however there are a few exceptions that give birth to live young. Sexual dimorphism is apparent in many lizard species where males tend to be larger than females with more colorful markings used to attract mates during breeding season