Lizards, being a suborder of the class of reptiles, are its largest group. There are more than 3,500 species and live on all continents except Antarctica. In this article we will look at the internal structure, skeleton, physiological characteristics of the lizard, species and names of their families.

Lizards are amazing creatures, which are distinguished from other representatives of the fauna by several interesting facts. The first fact is the size of representatives of different lizard populations. For example, the smallest lizard Brookesia Micra is only 28 mm long, while the most major representative This group of reptiles - the Indonesian monitor lizard, also known as the Komodo dragon, has a body length exceeding 3 meters, with a weight of about one and a half quintals.

The second fact makes these reptiles popular not only among biologists, but also ordinary people, is why and how a lizard casts its tail. This ability is called autotomy and is a method of self-preservation. When a lizard runs away from a predator, it can grab it by the tail, which actually poses a threat to the life of the reptile. In order to save their lives, some species of small lizards are able to shed their tail, which grows back after some time. To avoid large blood loss during autotomy, the tail of the lizard is equipped with a special group of muscles that contract blood vessels.

In addition to everything listed above, lizards in nature have the quality of skillful camouflage, adapting to color scheme environment. And some of them, especially the chameleon, can take on the color of a neighboring object in a matter of moments. How does this happen? The fact is that the skin cells of a chameleon, consisting of several almost transparent layers, have special processes and pigment, which under the influence of nerve impulses can shrink or unclench. At the moment the process contracts, the pigment gathers in the center of the cell and becomes barely noticeable, and when the process unclenches, the pigment spreads throughout the cell, coloring the skin a certain color.

Skeleton and internal structure of a lizard

The body of a lizard consists of parts such as head, neck, torso, tail and limbs. The body on the outside is covered with scales, consisting of smaller and softer horny formations compared to fish scales; there are no sweat glands on the skin. A characteristic feature is also a long muscular organ - the tongue, which is involved in feeling objects. The eyes of a lizard, unlike other reptiles, are equipped with a movable eyelid. The muscles are more developed than those of reptiles.

The lizard's skeleton also has some features. It consists of the cervical, shoulder, lumbar and pelvic sections, which are connected by the spine. The skeleton of a lizard is built in such a way that, when fused, the ribs (the first five) form a closed sternum from below, which is characteristic feature of this group of reptiles compared to other reptiles. The chest performs a protective function, reducing the risk of mechanical damage internal organs, it can also increase in volume during breathing. The limbs of the lizard, like other terrestrial animals, are five-fingered, but unlike amphibians, they are located in a more vertical position, which ensures some elevation of the body above the ground and, as a result, more fast travel. The long claws with which the reptile's paws are equipped also provide significant assistance in movement. In some species they are especially tenacious and help their owner to deftly climb trees and rocky terrain.

The lizard skeleton differs from other groups of terrestrial fauna in the presence of only 2 vertebrae in the sacral spine. Also a distinctive feature is the unique structure of the caudal vertebrae, namely in the non-ossifying layer between them, thanks to which the lizard’s tail is painlessly torn off.

What are the similarities between a lizard and a newt?

Some people confuse lizards with newts - representatives of the infraorder. What are the similarities between a lizard and a newt? Representatives of these two superclasses are similar to each other only in appearance; the internal structure of newts corresponds to the anatomy of amphibians. However, from a physiological point of view, both lizards and newts visually look the same: a snake-like head, movable eyelids on the eyes, a long body with five-fingered limbs on the sides and sometimes with a crest on the back, a tail capable of regeneration.

Lizard food

The lizard is a cold-blooded animal, that is, its body temperature changes depending on the ambient temperature, so these reptiles are most active during the day, when the air warms up the most. Most of them are carnivorous lizards, the species and names of which include more than one thousand individuals. The prey of lizard predators directly depends on the size of the reptile itself. Thus, small and medium-sized individuals feed on all sorts of invertebrate animals, such as insects, spiders, worms, and mollusks. The victims of large lizards are small vertebrates (frogs, snakes, small birds or lizards). The exception is the Komodo dragon, which, due to its large size, can afford to hunt larger game (deer, pigs and even small buffalo).

Another part of the lizards are herbivores, eating leaves, shoots and other vegetation. However, there are also omnivorous species, such as Madagascar geckos, which eat plant foods (fruits, nectar) along with insects.

Classification of lizards

The diversity of lizards is quite impressive and includes 6 superfamilies, collectively divided into 37 families:

• Iguanas.
• Geckos.
• Skinks.
• Fusiform.
• Monitor lizards.
• Worm-shaped.

Each of these infraorders has initializing features determined by the conditions of its habitat and its intended role in the trophic chain.

Iguanas

Iguanas are an infraorder with many varieties of life forms, in which not only the external, but often also the internal structure of the lizard differs. Iguanas include such well-known families of lizards as the iguana, agamidae and chameleon family. Iguanas prefer warm and humid climate, therefore, their habitat is the southern part of North America, South America, as well as some tropical islands (Madagascar, Cuba, Hawaii, etc.).

Representatives of the infraorder iguanas can be recognized by their characteristic lower jaw, which is strongly elongated due to pleurodont teeth. Also distinctive feature Iguanas are distinguished by the presence of a spiny crest on the back and tail, the size of which is usually greater in males. The paw of the iguana lizard is equipped with 5 fingers, which are crowned with claws (in arboreal species the claws are much longer than in terrestrial representatives). In addition, iguanas have growths on the head that resemble a helmet and throat pouches, which serve as a threat signaling tool and also play an important role in mating.

The body shape of iguanas mainly comes in two types:

1. A tall body with compressed sides, which smoothly turns into a thickened tail. This body shape can mainly be found in arboreal species, for example in the genus Polychrus in its South American habitat.
2. A flattened, disc-shaped body is found in representatives of iguanas living on the ground.

Gecko-like

The infraorder Geckoformes includes the families Cepcopods, Squamopods and Eublepharaceae. Home and common feature All representatives of this infraorder have a special chromosome set and a special muscle near the ear. Most geckos do not have a zygomatic arch, and their tongue is thick and not forked.

• The family of Gecko (grass-toed) lizards has lived on Earth for more than 50 million years. The lizard's skeleton and physiological features are adapted to live all over the world. They have the most extensive habitat both in hot climatic zones, and in temperate latitudes. The number of species in the family is more than a thousand.
• The Scalyfoot family is one of those very similar in appearance to snakes. They can be distinguished from snakes by the characteristic clicking sound that they are able to make to communicate with each other. The body, like that of snakes, is long, smoothly turning into a tail, which is adapted for autotomy. The lizard's head is covered with symmetrical scutes. The scalefoot population includes 7 genera and 41 species. Habitat: Australia, Guinea and nearby land areas.
• The Eublepharidae family are small lizards about 25 cm long with variegated colors, leading a nocturnal lifestyle. Carnivores, feed on insects. They live on the American, Asian and African continents.

Skinks

Representatives of skink-like lizards are common on all continents with temperate, tropical and subtropical climates. These are mainly land dwellers, although there are also semi-aquatic individuals, those that spend a larger period of their life in trees. This infraorder includes the following families:

Spindle lizards

The infraorder of fusiform lizards is characterized by small scales with unfused bony plates below. Among the spindle-shaped lizards, there are both legless species and lizards with a normal body structure with five-fingered limbs. The infraorder includes three families:

• The Xenosaur family differs from other families in having developed limbs and heterogeneous scales. Highlights the presence of movable eyelids and auditory openings. The family includes only two genera with habitats in Central America and China.
• The Veretenitaceae family has strong jaws equipped with blunt teeth. These are mainly carnivorous lizards that give birth by viviparity. The family has about 10 genera and 80 species, living mainly on the American continent. The size of adult individuals varies around 50-60 cm.
• The Legless family has only two species with a habitat in Mexico and California. They are distinguished by the absence of limbs, auditory openings and bone plates.

Monitor lizards

The infraorder Varanidae includes one genus - Monitor Lizards - and about 70 species. Monitor lizards live in Africa, with the exception of Madagascar, Australia and New Guinea. The largest species of monitor lizard, the Komodo Dragon, is a real record holder among all types of lizards in terms of size, its length reaches 3 meters and its weight is more than 120 kg. His dinner could easily be a whole pig. The smallest species (Short-tailed) does not exceed 28 cm in length.

Description of the Varan lizard: elongated body, elongated neck, limbs in a semi-straightened position, forked tongue. Monitor lizards - singular gender lizards in which the skull is completely ossified and has open ear openings on the sides. The eyes are well developed, equipped with a round pupil and a movable eyelid. The scales on the back consist of small oval or round plates, on the belly the plates take a rectangular shape, and on the head they are polygonal. The powerful body ends with an equally powerful tail, with which monitor lizards are able to defend themselves, causing strong blows on the enemy. In lizards leading an aquatic lifestyle, the tail is used for balancing when swimming; in arboreal species, it is quite flexible and tenacious, helping to climb branches. Monitor lizards differ from most other lizards in the structure of their heart (four chambers), similar to mammals, while the heart of lizards from other infraorders has three chambers.

In terms of lifestyle, monitor lizards are dominated by terrestrial species, but there are also those that spend a lot of time in water and in trees. The lizard's body is adapted to living in various biotopes; they can be found in the desert and in wet forests, and on the sea coast. Most of them are predators, active in daytime days, only two species of monitor lizards are herbivores. The prey of carnivorous lizards are various mollusks, insects, fish, snakes (even poisonous ones!), birds, reptile eggs, other types of lizards, and large monitor lizards often become cannibals, eating their young and fragile relatives. The entire genus of monitor lizards belongs to oviparous lizards.

Monitor lizards are important not only as a link in the trophic chain for their habitat, but also for anthropological activities. Thus, the skin of these lizards is used in the textile industry as a material for the manufacture of various haberdashery and even shoes. In some states, the local population eats the meat of these animals. In medicine, monitor lizard blood is used to make antiseptics. And, of course, these lizards often become inhabitants of terrariums.

Worm-like lizards

The infraorder of worm-like lizards consists of one family, the representatives of which are small, legless individuals, externally similar to worms. They live on the ground and lead a burrowing lifestyle. Distributed in the forest zone in Indonesia, the Philippines, India, China, New Guinea.

A lizard is an animal that belongs to the class reptiles (reptiles), order Squamate, suborder lizards. In Latin, the suborder of lizards is called Lacertilia, previously the name was Sauria.

The reptile got its name from the word “lizard,” which comes from the Old Russian word “skora,” meaning “skin.”

The largest lizard in the world is the Komodo dragon

The smallest lizard in the world

The smallest lizards in the world are the Haraguan sphero (Sphaerodactylus ariasae) and the Virginia round-toed gecko (Sphaerodactylus parthenopion). The size of the babies does not exceed 16-19 mm, and the weight reaches 0.2 grams. These cute and harmless reptiles live in the Dominican Republic and the Virgin Islands.

Virginia round-toed gecko (Sphaerodactylus parthenopion)

Where do lizards live?

Various species of lizards live on all continents except Antarctica. Representatives of reptiles familiar to Russia are real lizards that live almost everywhere: they can be found in fields, forests, steppes, gardens, mountains, deserts, near rivers and lakes. All types of lizards move well on any surface, firmly clinging to all kinds of bulges and irregularities. Rock species of lizards are excellent jumpers; the jump height of these mountain inhabitants reaches 4 meters.

Large predators, such as monitor lizards, hunt small animals - snakes, their own kind, and also happily eat the eggs of birds and reptiles. The Komodo dragon, the largest lizard in the world, attacks wild boars and even for buffalo and deer. The moloch lizard feeds exclusively, while the pink-tongued skink eats only terrestrial mollusks. Some large iguanas and skink lizards are almost entirely vegetarian, their menu consisting of ripe fruits, leaves, flowers and pollen.

Lizards in nature are extremely careful and agile; they approach their intended prey furtively, and then attack with a swift dash and capture the prey in their mouths.

Komodo monitor lizard eating buffalo

Lizards are reptiles. Most of them have a long tail and 4 legs. But there are also types of lizards that have no legs at all. Only specialists can distinguish them from snakes. The species diversity of this group of reptiles is enormous. They differ not only in size, body structure and coloring, but also in habits. Moreover, people often call reptiles lizards that are not lizards. To avoid making mistakes, it is useful to know what types of lizards there are.

Data especially lives in many places

general description

These reptiles thrive in forests, mountains, steppes and deserts. Some species of lizards have adapted to live in water.

Most reptiles are small in size from 20 to 40 cm, but there are also very large lizards, for example, pearl lizards. Its body length exceeds 80 cm. Giant lizards also live on our planet. It's about about Komodo dragons. Their height can reach 3 meters.

Separately, it is worth mentioning the very small lizards. On average, their height barely reaches 10 cm. The smallest of them are considered to be South American geckos - their body length with tail rarely exceeds 4 cm.

Reptiles have varied colors. Most often, their scales are painted in colors that allow them to better camouflage on the ground: green, brown and gray.

Some representatives of this group of reptiles have a very bright color, consisting of red or blue colors.

Lizards have several characteristic features:

1. They have highly mobile eyelids, for example, snakes, which are their closest relatives, have fused eyelids, so they practically cannot move their eyeballs.
2. These reptiles can get rid of their tail if necessary. When attacked by a predator, the animal breaks its spine and throws away the organ, which wriggles for some time, distracting the enemy’s attention.
3. Lizards do not have vocal cords, so they do not make sounds.
4. They have small ears. You can find them on both sides of the head.

Scientists know of only one species that makes at least some sounds - this is the lizard of Stechlin and Simon. In case of danger, it is capable of emitting a thin squeak.

Features of reproduction

The number of matings in lizards depends on their size. Large reptiles breed only once a year, while small ones are able to mate several times per season.

Males often fight for females. If one of them is larger, then the smaller one soon leaves the battlefield. When both fighters are in equal weight classes, then serious bloodshed can escalate. The winning male receives a female as a reward.

Can lay up to 18 eggs

In some species, the sex ratio is disrupted, but the lizards do not disappear. The fact is that females begin to lay eggs without the participation of males - this is the so-called parthenogenesis.

Lizards reproduce in two ways: with eggs and viviparity. Small species lay up to 18 eggs at a time. Large reptiles lay only a few pieces.

In most cases, females hide their clutches in the ground, sand, under stones or in the burrows of rodents they have killed. The period of egg maturation lasts from several weeks to 1.5 months. After the babies appear, the female loses all interest in them. Young lizards begin to live an independent life.

Pregnancy in viviparous species lasts 3 months. As a rule, the gestation period occurs in winter. The young are born in winter.

In this video you will learn more about lizards:

Orders of reptiles

Biologists divide all lizards into 6 orders, each of which includes about thirty families. The orders of reptiles are:

1. Skink-like. The order is distinguished by rich species diversity. It includes real lizards, widely represented in Russia, but most species live in tropical areas of the planet. Skink-like reptiles are found in South America and Africa, Madagascar and Cuba. Some varieties were discovered by scientists in the Sahara Desert.
2. Iguanas. This order includes 14 families of reptiles. The most famous of these is the chameleon, found in South America and Madagascar.
3. Gecko-like. Reptiles belonging to this order are considered rare. It includes lizards that do not have legs. They are found in Australia.
4. Fusiform. These include monitor lizards.
5. Worm-like lizards. These are the so-called scale insects. Externally, reptiles look more like huge earthworms. They can be found in the tropical rainforests of Indochina, Indonesia and Mexico.
6. Monitor lizards. These lizards are very large. Their weight often exceeds 5 kg. There are a lot of legends about them.

There is only one type of poisonous lizard - the poisonous lizard. When attacking their prey, they not only bite it, but also inject dangerous poison under the skin.

Some species can be pets

Pets

More and more people are keeping unusual pets in their homes. These can be insects, spiders and reptiles. Lizards take up the lion's share of this list. The reason for such popularity of reptiles lies in their cute appearance, calm behavior and relative friendliness. Lizards can easily replace a cat or a dog.

Panther chameleon

Furcifer pardalis is native to Madagascar. The lizard looks very bright, and its color largely depends on the place where it was born. Males can reach a length of 50 cm, but only in natural conditions. When kept at home, their body length rarely exceeds 25 cm. Females are even shorter. The lifespan of a panther chameleon does not exceed 6 years.

Females have a less bright color, which is different regions their habitats are almost the same. Males, on the contrary, are very bright and very different from each other. By their appearance, experienced specialists can determine where this or that individual appeared. The most popular varieties are:

1. Ambilobe chameleon. Born in the northern part of the island between two villages.
2. Sambava. Lives in the northeastern part of Madagascar.
3. The tamatawe chameleon is an inhabitant of the coastal part in the east of the island.

Easily feed from people's hands

At home, the panther chameleon should be kept in a terrarium. In the first months of life, a lizard needs a small home measuring 30x30x50 cm, but then it will need a larger home.

To bring the pet's living conditions closer to natural ones, branches, artificial and live plants are placed inside the terrarium. Of the latter, dracaenas and ficuses should be highlighted. Chameleons love to climb steep surfaces, which means that the serpentarium should contain driftwood and vines. The top of the dwelling must be tightly closed. If the lid is removed, the chameleons, despite their slowness, will quickly escape.

Panther and other types of chameleons do not like human contact. They love peace. If you take the reptile in your arms, then you need to do this only from below. Seeing movement from above, the reptile will regard it as a threat. Over time, chameleons get used to their owners and even begin to recognize them. They readily approach people while feeding.

This reptile prefers to live in close proximity to bodies of water, on the banks of which there are large stones or branches. The agama basks on them on sunny days.

The lizard has strong paws with large claws, which are not weapons, but a tool for convenient movement on various surfaces. A strong and wide tail allows the reptile to swim quickly.

The water agama is considered a large lizard. Taking into account the tail, the length of the female can reach 60 cm. Males are even larger - up to 1 meter. Males differ from females not only in size, but also in color. Moreover, these differences in young lizards are rather weakly expressed.

To keep a water agama at home you will need a very large terrarium. Young individuals can huddle in a 100-liter aquarium for some time, but then the living space for them will have to be significantly expanded.

It’s not for nothing that Agama is called a water creature – she loves to be in the water

Thick branches must be placed inside the terrarium. You can use paper and coconut shavings as a backing. But sand won't do - the lizard will eat it.

The terraria should have a heating zone with a constant air temperature of +35 °C. It is better to provide heating with the help of lamps, since lizards spend most of their time climbing on snags.

Agamas love to swim, so you need to place a pond inside the terrarium. In addition, you will have to maintain air humidity at least 60%. This can be done using a spray bottle.

There should not be 2 males in one terrarium. They will not be able to get along and will definitely fight.

The leopard gecko or spotted gecko is perhaps the most popular species among those who like to keep exotic animals at home. This lizard is very calm and peaceful. She feels great in small terrariums. The gecko is easy to care for. In addition, this type of reptile is distinguished by a variety of colors.

In nature, the leopard gecko lives in the dry steppes and rocky semi-deserts of Afghanistan, Iran and Pakistan. The lizard is active at dusk and early morning. At this time, the air temperature is most comfortable for her.

Spotted geckos prefer to live alone. They jealously guard their territory. Males prefer to communicate with females only during the mating period.

One gecko will feel great in a 50 liter terrarium. However, if the owner plans to breed these reptiles, then he will have to buy a larger terrarium.

Leopard gecko cannot walk on smooth terrain

cannot climb on smooth surfaces, so the home does not need to be covered with a lid. But if there are other pets at home, especially cats, then it is better to close the terrarium.

You can safely keep several females at once in one house if they are of the same age and size. There will be no hostility between them. But the males will certainly fight. Moreover, males do not get along with females. They will take food from females and kill them, so males should be kept alone.

Spotted geckos should have areas of high and low temperature in their terrarium. The maximum temperature is +32 °C, the minimum is not lower than +22 °C. This parameter must be monitored with two thermometers. Overheating or hypothermia will lead to illness in your pet.

Collared iguana

This medium-sized lizard lives in the southeastern United States. Maximum length its length, including its tail, is 35 cm. In natural conditions, it lives for about 8 years, and in captivity - no more than 4.

The collared iguana is a very strong and fast predator. According to biologists, if its size were comparable to the size of monitor lizards, it would easily displace the latter. This reptile effectively hunts other reptiles and rodents. She does not disdain insects either.

The iguana moves very quickly. Accelerating to a speed of 26 km/h, it attacks its prey and kills it with its powerful jaws in a few movements.

The lizard has a high metabolism, so keeping it at home is not easy, since you have to feed it often. Large cockroaches, beetles, and mice serve as food.

An iguana needs a spacious enclosure with an ultraviolet heater. You can keep it in a terrarium, but then it must be very large. The temperature in the lizard's home should be maintained at +27 °C, and in the heating zone - up to +41−43 °C. There is no need to make a separate pond, just install a drinking bowl. You should spray water from a spray bottle from time to time.

When interacting with iguanas, you must be careful. They have a hard time getting used to human hands and, if handled carelessly, can cause injury with their jaws.

Lizards- suborder scaly reptiles, the largest group of modern reptiles, currently numbering more than 3,500 species, grouped into 20 families and almost 350 genera. Lizards can be found on all continents except Antarctica. and each of them is characterized by certain groups of these animals. In Europe these are real lizards, in Asia - agamas and some geckos, in Africa - belt-tailed lizards, and in Australia - monitor lizards and scale-tailed lizards.

The greatest species diversity of lizards is in tropical and subtropical zones Lands, in countries with temperate climate there are fewer of them, and only one species reaches the Arctic Circle - the viviparous lizard (Lacerta vivi-raga). Lizards inhabit a wide variety of biotopes on our planet - from arid deserts to tropical rain forests and subalpine meadows, descend into the deepest gorges and climb mountains to a height of up to 5 thousand m above sea level, to the zone of eternal snow.

Most lizards live on the surface of the earth, but many of them penetrate into its thickness (many skinks) or rush upward into the crowns of trees (many agamas and geckos). And lizards like flying Dragon(Draco volans) or the lobe-tailed gecko (Ptycho-zoon kuhli), are trying again to do what was already done by reptiles many millions of years ago - to master the airspace. The sea element is also no stranger to lizards - marine iguanas (Amblyrhynchus cristatus) live on the Galapagos Islands, swimming and diving beautifully. seaweed which they feed on.

Appearance lizards are so diverse that it is difficult to name any characteristic feature. Moreover, lizards have so many common features with snakes, that sometimes even a specialist finds it difficult to distinguish them. It’s not for nothing that lizards and snakes are only suborders of the same order. Thus, representatives of 7 families of lizards in in full force or partially deprived of legs; in our country these are the spindletail (Anguis fragilis) and the yellowbell (Ophisaurus apodus).

Holo-eyes, like snakes, have fused and transparent eyelids, many lizards have barely noticeable (or even completely absent) ear openings, and, finally, there are poisonous lizards - poisonous teeth, living in the USA and Mexico. Many lizards have a very bizarre appearance due to the presence of various skin outgrowths and folds in the form of ridges, bumps and horns. As an example, just remember the Australian lizard - Moloch horridus, absolutely harmless, but with a terrifying appearance.

The coloring of many lizards is variegated and varied, and in some species it can vary depending on the physiological state. There are such lizards in our country. Thus, the color of the steppe agama (Tgarelus sanguinolenta) becomes brighter when high temperatures or during mating tournaments - at this time the males develop a characteristic blue “beard”. However, most lizards have camouflage coloring, making them invisible against the surrounding background.

For example, lizards that live in the desert are often colored yellow, gray or brown, and green tropical forest- in bright green. The appearance of lizards is closely related to their lifestyle. Tree species have tenacious claws and tails or special pads on their toes that allow them to stay on branches in the most unimaginable positions.

Thanks to such pads, covered with numerous microscopic hooks, some geckos can even stick to glass. Such are the leks (Gecko gekko), the Madagascar day geckos (Phelsuma) and many other geckos. Lizards that lead a burrowing lifestyle have reduced or absent limbs and a serpentine body. These characteristics are most clearly expressed in worm-like lizards of the genus Dibamus, common in Indochina, the Indo-Australian and Philippine islands and New Guinea.

Most lizards move very quickly, but I especially want to note the American cnemidophores (Cnemidophorus), which walk on their hind legs using their tail to maintain balance. For their speed of movement, these lizards received a second name - runner lizards. But the Australian frilled agama (Chlamydosaurus kingi) is not inferior to them in terms of speed of movement. A helmed basilisk(Basiliscus plumifrons) from Central America, reaching a length of 80 cm, moves on its hind legs with such speed that it can run not only on land, but also on water.

Many lizards can make certain sounds. Some of them hiss like snakes (for example, monitor lizards). Others make more varied sounds. These are, first of all, geckos. They make squeaks, clicks, chirps and the like, using not only their tongue, but also the friction of the scales on their tail. The skink gecko (Tegatoscincus scincus), living in the Central Asian republics of our country, has such a “musical” tail.

The largest modern lizard is considered to be the giant Indonesian monitor lizard (Varanus komodoensis) from Komodo Island, which reaches a length of 3 m and weighs up to 120 kg. And the smallest lizard, not exceeding 4 cm in length, is the South American gecko - Spherodactylus elegans.

Lizard nutrition

Most lizards are predators. The size of the prey depends on the size of the lizards themselves. Small and medium-sized lizards feed mainly on various insects, spiders, worms, mollusks and small vertebrates. Larger lizards eat larger prey - fish, amphibians, other lizards and snakes, birds and their eggs, and various mammals.

Fewer lizards are herbivorous. However (just as was noted in the essay about turtles), many lizards, eating mainly plant foods, willingly add food of animal origin to their “menu” and, conversely, predators - plant food.

Moreover, in most herbivorous lizards, the young initially feed on insects and only over time switch to the food of their parents. Food specialization among lizards is relatively rare, but nevertheless it occurs, and this must be taken into account. Thus, the feeding of marine iguanas predominantly on one type of algae is of exclusively theoretical and general educational interest, and the narrow food specialization of some roundheads on ants or termites may also be of practical interest to us.

Lizard Reproduction

The reproduction of lizards (as well as turtles) is not particularly diverse. During the breeding season, which in countries with a temperate climate and a clearly defined change of seasons occurs in the spring, and in tropical regions can be completely acyclical, male lizards organize mating tournaments and court females, after which they mate with them. Most lizards lay eggs.

Typically, eggs have a thin, leathery shell, less often (mainly in geckos) a dense, calcareous shell. Number of eggs various types varies and can range from 1-2 to several dozen. The female lays eggs one or several times during the year, in a wide variety of, but always secluded places - in holes, cracks, under stones and snags, in tree hollows, etc.

Some geckos glue eggs to tree trunks and branches, in rocky outcrops, etc. In most cases, after laying eggs, lizards do not return to them. Only a few of them take care of their offspring. Among our lizards this is the yellow-bellied lizard (Ohisaurus apodus). Females of this species not only guard the clutch, but also look after it - periodically turning it over and cleaning it of debris.

Even for some time after the young yellowbellies hatch, the females continue to protect them and even give up food.
One of the forms of caring for offspring may include the ability of some lizards to delay the laying of eggs, waiting for the onset of conditions favorable for this. Thus, in the sand lizard, eggs can linger in the oviducts for 20 days. In others, for example, in the viviparous lizard (Lacerta vivipara), until hatching. These are different stages of the same process - ovoviviparity. But in some species of lizards (most often these are skinks) there is also a true viviparity, when the fibrous shell of the egg is reduced and part of the oviduct comes into contact with the chorion - that is, a semblance of a placenta is formed, with the help of which the embryo is nourished at the expense of the mother’s body.

One of the reasons that causes viviparity is the cold climate, so the percentage of viviparous species increases as you move north and into the mountains. It is interesting that even lizards of the same species, depending on the altitude above sea level, can either lay eggs or give birth to live young. For example, Tibetan roundheads lay eggs at an altitude of 2 thousand m above sea level, and are viviparous at an altitude of 4 thousand m.

Concluding the conversation about the reproductive biology of lizards, it is advisable to mention the so-called parthenogenetic reproduction, characteristic of some of them. Moreover, the species, as a rule, does not have males as such; females lay unfertilized eggs, from which, nevertheless, completely normal young ones hatch.

Parthenogenetic lizards in our country include the Armenian lizard (Lacerta armeniaca), white-bellied lizard (L. unisexualis), Dahl's lizard (L. dah1y) and Rostombekov's lizard (L. rostombekovi).

Lifespan of lizards. For many small species it is short, only 2-5 years, and sometimes even 1 year. But large lizards, primarily monitor lizards, can live in captivity for up to 50-70 years.

LIZARDS
(Lacertilia, Sauria),
suborder of reptiles. As a rule, small animals with well-developed limbs, the closest relatives of snakes. Together they form a separate evolutionary lineage of reptiles. Main hallmark its representatives are the paired copulatory organs of the male (hemipenises), located on both sides of the anus at the base of the tail. These are tubular formations that can turn out or retract inward like the fingers of a glove. The inverted hemipenises serve for internal fertilization of the female during mating. Lizards and snakes form the order of scaly animals - Squamata (from the Latin squama - scales, as a sign that the body of these reptiles is covered with small scales). One of the recurring trends in the evolution of its representatives was the reduction or loss of limbs. Snakes, one of the lineages of squamates with reduced limbs, make up the suborder Serpentes. The suborder of lizards comprises several highly divergent evolutionary lineages. For simplicity, we can say that “lizards” are all scaly animals, except snakes. Most lizards have two pairs of limbs, visible openings of the external auditory canal, and a movable eyelid; but some of them lack these signs (like all snakes). Therefore, it is safer to focus on the features internal structure. For example, all lizards, even legless ones, retain at least rudiments of the sternum and shoulder girdle (the skeletal support of the forelimbs); Both of these are completely absent in snakes.
Distribution and some species. Lizards are widespread throughout the world. Absent from Antarctica, they are found from the southern tip of other continents to southern Canada in North America and to the Arctic Circle in that part of Europe where the climate is moderated by warm ocean currents. Lizards are found from elevations below sea level, such as Death Valley in California, to 5500 m above sea level in the Himalayas. Known approx. 3800 of them modern species. The smallest of them is the round-toed gecko (Sphaerodactylus elegans) from the West Indies, only 33 mm long and weighing about 1 g, and the largest is the Komodo dragon (Varanus komodoensis) from Indonesia, which can reach 3 m in length and weighs 135 kg. Despite the widespread belief that many lizards are venomous, there are only two such species - the common lizard (Heloderma suspectum) from the southwestern United States and the related escorpion (H. horridum) from Mexico.

Paleontological history. The oldest fossil remains of lizards date back to the Late Jurassic (ca. 160 million years ago). Some of their extinct species were enormous in size. It is believed that Megalania, which lived in Australia in the Pleistocene (approx. 1 million years ago), reached a length of approx. 6 m; and the largest of the mosasaurs (a fossil family of long, slender fish-like aquatic lizards related to monitor lizards) is 11.5 m. Mosasaurs inhabited coastal sea ​​waters various parts of the planet approx. 85 million years ago. The closest modern relative of lizards and snakes is the rather large tuatara, or tuatara (Sphenodon punctatus), from New Zealand.
Appearance. The background color of the back and sides of most lizards is green, brown, gray or black, often with a pattern in the form of longitudinal and transverse stripes or spots. Many species are able to change color or its brightness due to the dispersion and aggregation of pigment in special skin cells called melanophores. The scales can be both small and large; they can be located close to each other (like tiles) or overlapping (like tiles). Sometimes they are transformed into spines or ridges. Some lizards, such as skinks, have bony plates called osteoderms inside their horny scales, which give the integument additional strength. All lizards molt periodically, shedding their outer layer of skin. The limbs of lizards are designed differently, depending on the lifestyle of the species and the surface of the substrate on which it usually moves. In many climbing forms, such as anoles, geckos and some skinks, the lower surface of the fingers is expanded into a pad covered with setae - branched hair-like outgrowths of the outer layer of the skin. These bristles catch on the slightest irregularities in the substrate, which allows the animal to move along a vertical surface and even upside down. Both the upper and lower jaws of lizards are equipped with teeth, and in some they are also located on the palatine bones (the roof of the oral cavity). The teeth are held on the jaws in two ways: acrodontally, almost completely fused with the bone, usually along its edge and not replacing, or pleurodontally - loosely attached to inside bones and changing regularly. Agamas, amphisbaenas and chameleons are the only modern lizards with acrodont teeth.
Sense organs. The eyes of lizards are developed differently, depending on the species - from large and well-seeing in diurnal forms to small, degenerate and covered with scales in some burrowing taxa. Most have a movable scaly eyelid (lower eyelid only). Some medium-sized lizards have a transparent “window” on it. In a number of small species it occupies most or the entire area of ​​the eyelid, attached to the upper edge of the eye, so that it is constantly closed, but sees as if through glass. Such “glasses” are characteristic of most geckos, many skinks and some other lizards, whose gaze as a result is unblinking, like that of snakes. Lizards with a movable eyelid have a thin nictitating membrane, or third eyelid, underneath it. This is a transparent film that can move from side to side. Many lizards have retained the parietal “third eye” characteristic of their ancestors, which is not capable of perceiving shape, but distinguishes between light and darkness. It is believed to be sensitive to ultraviolet radiation and helps regulate sun exposure as well as other behaviors. Most lizards have a noticeable opening in the shallow external auditory canal, which ends in the eardrum. These reptiles perceive sound waves frequency from 400 to 1500 Hz. Some groups of lizards have lost their auditory opening: it is either covered with scales or has disappeared as a result of narrowing of the auditory canal and eardrum. In general, these “earless” forms can perceive sounds, but, as a rule, worse than the “eared” ones. The Jacobson (vomeronasal) organ is a chemoreceptor structure located in the anterior part of the palate. It consists of a pair of chambers that open into the oral cavity with two small holes. With its help, lizards can determine chemical composition substances in the mouth and, more importantly, in the air and landing on their protruding tongue. Its tip is brought to the Jacobson's organ, the animal "tastes" the air (for example, to the proximity of prey or danger) and reacts accordingly.
Reproduction. Initially, lizards belong to oviparous animals, i.e. lay shell-covered eggs that develop for several weeks outside the mother's body before hatching. However, many groups of lizards have developed ovoviviparity. Their eggs are not shelled and remain in the female’s oviducts until completion. embryonic development, and the already “hatched” cubs are born. Only the widespread South American skinks of the genus Mabuya can be considered truly viviparous. Their tiny, yolkless eggs develop in the oviducts, likely receiving nutrition from the mother through the placenta. The placenta in lizards is a special temporary formation on the wall of the oviduct, in which the capillaries of the mother and embryo come close enough to each other so that the latter receives oxygen and nutrients. The number of eggs or young in a brood varies from one (in large iguanas) to 40-50. In several groups, for example, in most geckos, it is constant and equal to two, and in skinks and a number of American tropical geckos, there is always only one cub in the brood. Age of puberty and life expectancy. Puberty in lizards generally correlates with body size; in small species it lasts less than a year, in large species it lasts several years. In some small forms, most adults die after laying eggs. Many large lizards live to be 10 years or more, and one copperhead, or brittle spindle (Anguis fragilis), reached 54 years of age in captivity.
Enemies and methods of defense. Lizards are attacked by almost all animals that can grab and defeat them. These are snakes predator birds, mammals and humans. Methods of defense against predators include morphological adaptations and special behavioral techniques. If you get too close to some lizards, they will take on a threatening pose. For example, the Australian frilled lizard (Chlamydosaurus kingii) suddenly opens its mouth and raises a wide, bright collar formed by a fold of skin on its neck. Obviously, the effect of surprise plays a role in scaring off enemies. If many lizards are grabbed by the tail, they throw it away, leaving the enemy with a wriggling piece of debris that distracts his attention. This process, known as autotomy, is facilitated by the presence of a thin non-ossifying zone in the middle of all caudal vertebrae except those closest to the trunk. The tail is then regenerated.

Collier's Encyclopedia. - Open Society. 2000 .

See what "LIZARDS" is in other dictionaries:

- (Saurra), suborder of squamates. Appeared in the Triassic. Ancestors of snakes. The body is ridged, flattened, laterally compressed or cylindrical, of various colors. Skin covered with horny scales. Dl. from 3.5 cm to 4 m (monitor lizards). The front part of the skull is not... ... Biological encyclopedic dictionary

Suborder of reptiles of the order Squamate. The body ranges from a few cm to 3 m or more in length (Komodo dragon), covered with keratinized scales. Most have well-developed limbs. More than 3900 species, on all continents except Antarctica,... ... Big encyclopedic Dictionary

- (Lacertilia s. Sauria) reptiles with an anus in the form of a transverse slit (Plagiotremata), with a paired copulatory organ, teeth not in meshes; usually equipped with a front girdle and always have a sternum; in most cases with 4 limbs,... ... Encyclopedia of Brockhaus and Efron

The request for "Lizard" is redirected here; see also other meanings. ? Lizards ... Wikipedia

- (Sauria) suborder (or order) of reptiles of the order (or subclass) squamate. Body length from 3.5 cm to 3 m (Komodo dragon). The body is ridged, flattened, laterally compressed or cylindrical. Some have well-developed five-fingered... ... Great Soviet Encyclopedia

Lizards->) and a female. /> Viviparous lizards: male () and female. Viviparous lizards. Lizards, suborder of animals class. They are distinguished by the presence of limbs () and movable eyelids. Length from 3.5 cm to 4 m. The body is covered with keratinized scales. Ya are distributed to... ... Encyclopedia "Animals in the House"