Lizard, a scaly reptile closely related to snakes. Lizards live chiefly in warm regions. Many inhabit deserts and semiarid regions; others live in fields and forests. Most dwell on the ground; some burrow into the soil; still others spend much of their time either in trees or in water.
Basilisk, the common name of several tropical American lizards of the iguana family. The male has a crest on the back and tail and sometimes on the head. The most common species is green and brown, reaches a length of three feet (90 cm), and lives in trees. It is harmless.
The common basilisk is Basiliscus americanus of the family Iguanidae.
Chameleon, a tree-dwelling lizard having the ability to change color and to move each eye independently. The color change is involuntary, contrary to common belief, and is brought about by light, temperature, and nervous stimulation such as anger or fear. It is not related to the color of the substance on which the chameleon happens to be.
Under ordinary conditions, the rough skin of the chameleon is a dull brownish-green. Under stresses of fear or anger, the color changes to a vivid green; it turns brown or yellowish-gray in response to hunger, low temperatures, and strong sunlight. The males of some species may display a brilliant red dewlap (a loose fold of skin under the throat) during courtship or in comba
Chuckwalla, a stout lizard native to the southwestern United States. It grows to a length of about 18 inches (45 cm). The tail is thick and short. Young chuckwallas are brown with dark bands or other markings; older animals are a solid reddish brown. Chuckwallas feed on buds, flowers, and young leaves.The chuckwalla is Sauromalus obesus of the family Iguanidae
Dragon of Komodo
Dragon of Komodo, or Ora, the largest living lizard. It is named after Komodo, one of several small Indonesian islands on which it is found. This rough-skinned lizard has a long tail and dull, gray-brown to black scales. It grows to about 10 feet (3 m) in length and may weigh as much as 300 pounds (136 kg). Despite its bulk, the dragon of Komodo is agile enough to capture wild pigs and deer. It has been known to attack humans. Indonesians consider its eggs a delicacy. Because of destruction of its habitat, the dragon of Komodo is an endangered species.
Scientists think that the Komodo dragons’ environment may be one reason the animals have become so large. Komodo dragons live on only a few Indonesian islands, where the Komodos are the largest meat-eating animals. So, a living Komodo dragon seldom becomes supper for another animal. And it does not have to compete very much for its own supper.
The Komodo dragon mainly eats dead animals, but it also hunts, kills, and eats large prey. It has been known to eat deer, wild pigs, goats, and water buffaloes. Adults will sometimes eat young Komodo dragons, too. Komodo dragons have even killed a small number of people
Flying Dragon, a tree-dwelling lizard that can glide through the air from tree to tree. It grows to about eight inches (20 cm) long. A thin membrane covers false ribs extending outward from the flying dragon’s body. Supported by this membrane, the animal can glide 50 feet (15 m) or more after leaping from a tall tree. It can turn in the air, and even return to the tree from which it jumped. The flying dragon feeds on insects and spiders. There are about 40 species of flying lizards in southeast Asia. Most are brightly colored.
Flying lizards belong to the family Agamidae. The flying dragon is Draco volans.
Gecko, any of more than 400 species of small harmless lizards found in warm climates. The gecko’s name is derived from the sound of the cry of one species. Geckos are most numerous in southeastern Asia, Africa, and Australia. The largest gecko is the tokay of Malaysia, 10 to 14 inches (25 to 36 cm) long. Two geckos, both about 4 inches (10 cm) long, are native to the southwestern United States—the banded gecko (brownish with yellow bands) and the leaffingered gecko.
The gecko’s tapering head and short, flat body are covered with tiny scales that give the skin a soft appearance. Many species have brittle tails that break off easily. The leaf-fingered gecko is among the many species that have clinging pads at the tips of their toes, enabling them to run on walls and ceilings. Geckos move about only at night, feeding mainly on insects.
Glass Snake, a legless lizard of southern United States. The name refers to the brittle tail, glassy appearance, and snakelike body and motions. Fully grown, glass snakes range from 18 inches (45 cm) to more than three feet (90 cm) long; two-thirds of this length may be tail. The body is covered with green-spotted black, olive, or brown scales. The underside is greenish-white.
When seized, a glass snake may shed most of its tail, which continues to wriggle while the lizard escapes. The animal later grows a new tail, which is shorter than the old one and lacks vertebrae.
Species in the United States are: Ophisaurus ventralis; O. attenuatus; and O. compressus. Glass snakes belong to the family Anguidae.
Horned Toad, or Horned Lizard, a desert lizard of the western United States and Mexico. There are 15 species, ranging in length from two to eight inches (5 to 20 cm). The horned toad is named for the rows of horny projections on its head and body, and for its resemblance to the toad. It is yellowish, brown, reddish, or gray and has dark spots on the back. The horned toad feeds primarily on ants. The female lays 6 to 40 eggs in a burrow in the sand. The young hatch in six to eight weeks. When threatened by a predator, some species spurt tiny jets of blood from pores in their eyelids. Other species make a hissing sound or inflate their bodies with air.
Horned toads belong to the iguana family, Iguanidae. The most common species are the Texas horned toad, Phrynosoma cornutum; desert horned toad, P. platyrhinos; and the coast horned toad, P. coronatum.
Iguana, a large lizard of tropical America. The largest iguanas attain a length of about six feet (1.8 m), over half of which is tail. The iguana has black, brown, or green scales. A spiny ridge extends down its back and a dewlap (skin flap) hangs from its throat. Some species live in trees near the water, others are ground dwellers. All are good swimmers. Iguanas live chiefly on fruit, vegetation, and birds’ eggs. Both the flesh and the eggs of iguanas are eaten.
Iguanas eat insects, fruit, flowers, and leaves.
The grayish-green common iguana is the largest species. The horned rhinoceros iguana lives in the West Indies. The marine iguana lives in the Galápagos Islands off Ecuador.
Skink, a family of small, ground-dwelling lizards. Skinks are usually less than one foot (30 cm) in length, and have conical or blunt-shaped heads, cylindrical bodies, and tapering tails. There are about 1,280 species, found on all continents except Antarctica. Skinks are most numerous in Africa, Asia, Australia, and the islands of the Western Pacific.
Many skinks have two pairs of well-developed limbs; some have only small hind limbs; and others are limbless. Skinks are usually some shade of olive or brown and are often marked with stripes, crossbars, or spots. The smooth, flat overlapping scales covering their bodies give skinks a glossy or shiny appearance.
The skink’s tail often serves as a protective device. When seized it easily breaks off and the skink escapes. A new tail grows shortly afterwards. Most skinks feed on small invertebratesmainly insects. Some are vegetarians. Some skinks lay eggs; others bear live young.
There are 15 species in the United States. Among them are the sand skink, which is tan or white with dark stripes; the five-lined skink, black with light stripes; and the ground skink, brown with black stripes.
Skinks make up the family Scincidae. The sand skink is Neoseps reynoldsi; the five-lined skink, Eumeces obsoletus; the ground skink, Scinella lateralis.
Slowworm, a limbless lizard that inhabits forests and grasslands of Europe, western Asia, and Algeria.
Tuatara, a lizardlike reptile found on several small islands off New Zealand. One species inhabits about 30 islands. In 1990, it was determined that a second species exists on one island.
Tuataras have remained almost unchanged for some 200 million years. Adults are greenish-brown above with gray or white speckles. The underparts are lighter. A crest of white spines grows along the neck and back. An adult male is about two feet (60 cm) long and weighs about two pounds (900 g); the female is smaller.
Tuataras are sluggish during the day but active at night when they hunt for such food as insects, spiders, snails, and earthworms. They live in burrows made by shore birds, especially petrels. In summer, the birds and the tuataras share the burrows. If a tuatara cannot find a bird burrow, it digs its own.
In spring, the female lays from 8 to 15 soft, white eggs that are about one inch (2.5 cm) long. The young hatch more than a year later and are about six inches (15 cm) long. Their bodies are brown or gray with stripes on the throat. Tuataras do not reach sexual maturity until they are about 20 years old. Some specimens have lived in captivity for more than 50 years. Many zoologists believe that in their natural habitat tuataras may live for more than 100 years.
Tuataras, which are endangered, are protected by the New Zealand government.
The two species of tuatara are Sphenodon punctatus and (the more recently named) S. guntheri. They are the only living members of the order Rhyncho-cephalia.