Lizards are the most diverse group of reptiles, with more than 4000 known species in the world, mainly distributed in the tropics. There are great differences in body size, from a few centimeters of the Caribbean gecko to nearly three meters of the Komodo dragon. lizard
Some species, known as lizards, have degenerated feet, leaving only traces of foot structure. They can be distinguished from snakes by their eyelids and ears.
Many lizards, such as chameleons, can change their colors in response to environmental changes or stress.
Most species are carnivorous, feeding on insects, earthworms, snails and even mice. But there are also cactus or seaweed as the staple food, or omnivorous.
Any of various reptiles of the suborder Sauria. Serpentes, which is closely related to Serpentes, accounts for 95% of the total reptiles. There are more than 3000 species in 18 families. The tropical area has the most species and quantity. From the Arctic to southern Africa, South America and Australia. Lizards have the largest differences in body shape and size among reptiles. Body length ranges from 3 cm (1 inch, gecko) to 3 m (10 feet, lizard). The lightest weight is less than 1G, and the heaviest is more than 150kg. The body is long and slender, with a long tail and four limbs. Besides nostrils, mouth, eyes and cloacal openings, the body surface is covered with scales, a pair of eyes and a pair of earholes. If there is no external ear foramen, the tympanic membrane is on the surface, some species are under the scales of the head and body, and there are bone scales in the dermis. The scales are coated with keratin.
Some lizards have scaly organs, scales serrate, margin prominent bristles, may be tactile. Many lizards, especially chameleons and lizards, can change their body color from bright green to dark chocolate brown, and their body lines and stripes can also flicker. The mechanism of discoloration is the movement of pigment particles in melanocytes. The color is light when the particles are concentrated and dark when they are dispersed. Some lizards have extensible skin folds on the neck, horns or helmets on the head, or spines or folds on the throat. The anterior part of the skull consists of thin cartilage and membranes. Most of the eyelids are movable. The orbital septum between the two eyes is thin and vertical. There is a temporal foramen on the bone rod formed by the retroorbital bone and the scaly bone. The palate can move relative to other parts of the skull. It has a square bone, and its mouth can be wide open for swallowing prey.
