Each of us, even though the picture, saw frogs and lizards, crocodiles and frogs - these animals belong to the class of amphibians and reptiles.The example given by us, is not the only one.There are actually many things.But how to tell who is who?The different amphibians and reptiles and how significant these differences?
Crocodile and toad can perfectly coexist in the same pond.Therefore, it is likely that it may seem as if they are relatives and have common ancestors.But this is a huge mistake.These animals belong to different taxonomic classes.Among them are many fundamental differences.And they are not only in the appearance and size.Crocodile and lizard - a reptile and frog and a toad - amphibians.
But, of course, amphibians and reptiles have some similarities.They prefer areas with warm climates.However, amphibians are choosing damp places near water better.But this is dictated by the fact that they multiply only in water.Reptiles are also not connected with reservoirs.They, on the contrary, prefer a more dry and hot regions.
Let's look at the structure and physiological features of reptiles and amphibians, and compare how they differ from each other.
Class Reptiles (reptiles)
Class reptiles or reptiles - this land animals.The name they got thanks to a method of transportation.Reptiles do not go on the ground, they crawl.It was the first time the reptile is completely switched from water to land-living.The ancestors of these animals are widely spread across the ground.An important feature of reptiles is internal fertilization and the ability to lay eggs, rich in nutrients.They are protected by a dense shell, which includes calcium.It is the ability to make egg-laying reptiles is contributed to the development of the reservoir on land.
structure reptile reptiles
Body has strong education - scales.They are densely covered with the skin of reptiles.This protects them from moisture loss.Reptile skin is always dry.Evaporation therethrough occurs.Therefore, snakes and lizards are able to live in the desert, without experiencing discomfort.
Breathe reptiles using fairly well-developed lungs.It is important that rapid breathing reptiles became possible thanks to the emergence of a fundamentally new parts of the skeleton.The thorax is the first time there is a reptile.It is formed by ribs extending from the vertebrae.On the ventral side they are connected to the sternum.Due to the special rib muscles mobile.This facilitates the expansion of the chest during inspiration.
Reptiles class has changed and by the circulatory system.This is due to the increasing complexity of the structure of the lungs.The vast majority of reptiles, three-chamber heart, they, like amphibians, two circulation.However, there are some differences.For example, in the ventricle is a partition.When the heart contracts it virtually divides it into two halves (right - venous, left - Arterial).Location main blood vessels more clearly delineates the arterial and venous flow.As a result - the body is supplied with blood reptiles, oxygen-rich, much better.Thus they have established a process output and intercellular exchange of metabolic products and carbon dioxide from the body.There are exceptions in the class of reptiles, an example - a crocodile.His heart quad.
large main artery of small and large circulation essentially the same for all groups of terrestrial vertebrates.Of course, no small differences, and there has not been.Reptiles in the pulmonary circulation disappeared cutaneous veins and arteries.Only the pulmonary vessels.
Currently, there are about 8 thousand. Reptiles.They are found on every continent, in addition, of course, Antarctica.Separate the four companies reptiles: crocodiles, scaly, turtles and pervoyaschery.
Breeding reptiles
Unlike fish and amphibians, reptiles internal reproduction.They are dioecious.The male has a special body, with which he enters into the cloaca of the female sperm.They penetrate the egg, then fertilization occurs.The eggs develop in the body of the female.Then, it puts them in a prepared place usually a pit dug.Outside the eggs of reptiles are covered with a dense calcium shell.They are the embryo and the supply of nutrients.From the egg comes out the larva do not like fish or amphibians, and capable of independent life of the individual.Thus, breeding of reptiles in principle to a new level.The embryo undergoes all stages of development in the egg.After hatching, it does not depend on the reservoir and could survive on their own.Typically, adults do not show concern for their offspring.
Class Amphibians
amphibians or amphibian - a frog, toads and newts.They are, with rare exceptions, always live near a pond.But there are species that live in the desert, such as the toad-water pot.In the rain it is gaining in subcutaneous fluid bags.Her body is inflated.It then buries itself in the sand and allocating large amounts of mucus, is experiencing a prolonged drought.Currently, there are about 3,400 species of amphibians.They are divided into two groups - tailed and tailless.The first group includes salamanders and newts, to the second - frogs and toads.
Amphibians are very different from the class of reptiles, example - the structure of the body organs and systems, as well as the method of reproduction.Like their ancestors the fish, they spawn in the water.To do this, amphibians are often looking for pools, separated from the main body of water.It happens the fertilization and larval development.This means that during the breeding amphibians have to go back to the water.This greatly hinders their resettlement and limits on movement.Only a few species have adapted to life away reservoirs.They give birth to offspring been formed.That's why these are called semi-aquatic animals.
Amphibians - the first of chordates, who developed the limbs.Due to this in the past they were able to enter the land.Naturally, this has caused a number of these animals changes not only anatomical, physiological and.Compared with the views remaining in the aqueous medium in amphibians broader chest.This has contributed to the development and complexity of the lungs.Amphibians improved hearing and vision.
Habitats amphibians
Like reptiles, amphibians prefer to live in warm regions.Normally frogs are found in damp places near water.But they can be seen and in the meadows and forests, especially after heavy rain.Some species thrive even in the deserts.For example, the Australian toad.It is very well adapted to experience a prolonged drought.In such conditions, other types of frogs certainly would have died quickly.But she has learned to accumulate vital moisture in subcutaneous pockets during the rainy season.Also in this period, she breeds, laying eggs in puddles.Tadpoles enough to completely convert one month.Australian toad in extreme conditions for its kind, not only found a way to reproduce, but also successfully seek out for themselves writing.
differences from reptiles, amphibians
Although at first glance it appears that amphibians are not much different from reptiles, it is not so.In fact, the similarity is not so much.Amphibians are less advanced and developed organs than the class of reptiles, an example - the larvae of amphibians have gills, while the offspring of reptiles are born with the generated light.In fairness it should be noted that the newts, and frogs, and turtles, and even a snake may well co-exist on the territory of one reservoir.Therefore, some people do not see significant differences in these squads, often confused, who is who.But fundamental differences do not allow you to combine these types in one class.Amphibians always depend on their place of residence, ie the reservoir, in most cases they can not leave it.Since reptiles are quite different.In case of drought they may make a small trip and find a more suitable place.
This is possible largely due to the fact that the skin of reptiles is covered with horny scales that do not allow moisture to evaporate.Reptile skin deprived of glands that produce mucus, so it is always dry.Their body is protected from drying out, which gives them a distinct advantage in dry climates.For reptiles characteristic of molt.For example, the body of a snake grows life.Her skin "wear out."They inhibit the growth, so every year it "resets" them.Amphibians naked skin.It is rich in glands secrete mucus.But the intense heat amphibian can get heat stroke.
ancestors of reptiles and amphibians
ancestors of amphibians were crossopterygian fish.From their paired fins and later formed five-fingered limbs.The external structure of the reptiles indicates that their ancestors were reptiles.This is evidenced by both anatomical and physiological similarities.Among vertebrates, they are the first units left the aquatic environment, and went ashore.For many thousands of years, they dominated over the other species.It puts an end to this reign of mammals.Why did it happen, not known for certain.There are a number of assumptions, most of which are supported by conclusive evidence.This is a global catastrophe caused by the fall of the meteorite, and the appearance of flowering plants and climate change.Subsequently, many reptiles returned to the aquatic environment.But the internal organs they were quite suitable for life on land.Currently, the representative of such species is the sea turtle.
differences in the structure of
Amphibians and reptiles breathe atmospheric air through the lungs.But the larvae of amphibians are stored gills.Reptiles also do not have them.Furthermore, reptiles more complex nervous system.They have the beginnings of the cerebral cortex, cerebellum, and more developed senses.Crocodiles, lizards and chameleons are better adapted to life on land.They have perfect hearing, sight, and well developed sense of taste, smell, touch.Taste buds also in amphibians are virtually absent.Although they have very well developed, acute sense of smell.
In reptiles complicated circulatory and excretory systems.Their blood in large vessels is best divided into arterial and venous.In addition, the reptile disappeared cutaneous vessels, which are very developed in amphibians.This is due to the fact that about half of the oxygen frogs and newts prepared by cutaneous respiration.Under the water, they do not use the lungs.Reptiles also similarly can not absorb oxygen.Therefore skin arteries and veins do not need them.They breathe exceptionally well-developed lungs.
amphibians and reptiles have a different number of parts of the spine.There are five reptiles and amphibians - four.In tailless species fins are missing.
difference in the way the breeding
fish, amphibians, reptiles vary considerably according to the method of reproduction.Reptiles fertilization is internal.Eggs are formed inside the female.Then, as a rule, it puts them in a pit excavated and treated dropwise with the top.Similarly behave like crocodiles and turtles.The young hatch fully developed, from the adults they differ only in size.There are also viviparous reptiles.They are "born" into the world formed in baby leathery shell.This method of reproduction is inherent in some types of snakes.Born baby breaks the shell and crawls.He leads an independent life.That ability to make egg laying in a solid shell gave an evolutionary advantage to reptiles, amphibians.This made it possible to settle them in different parts of the world.They exist in the forests, deserts, mountains and plains.The structural features of reptiles and allow them to live in water.
Amphibians reproduction takes place in the pond.Females lay their eggs in water.There also let male sperm that fertilize eggs.First hatch into larvae.It is only after two or three months they finally become young.
Lifestyle reptiles and amphibians
Many amphibians are born only in the water, and the whole adult life they spend on land.But there are types of amphibians such as newts, which do not leave the aquatic environment.Under unfavorable conditions such land species, like frogs, toads may come back into the pond.They feed on plant foods amphibians and invertebrates.They live long.Some species of frogs can live up to 8 years, and newts - only 3 years.
Features reptiles is that they do not depend on water.They are able to multiply and in its absence.Reptiles eat a variety of foods.The diet consists of small lizards, insects.Snakes hunt for rodents.They can eat the eggs and birds.Crocodiles and lizards prefer to herbivorous mammals - deer, antelope and even large buffalo.Turtles consume vegetarian food.Reptiles - real centenarians.Found tortoises, whose age is more than 200 years.Crocodiles can live 80 years, and snakes and lizards - up to 50.
Conclusions
Reptiles are different from amphibians on the following parameters:
1. habitats.Amphibians prefer damp and wet places near water.Reptiles are not linked to water.
2. The skin of reptiles deprived glands.It is dry and covered with scales.Amphibians contrary, it is dotted with glands that secrete large amounts of mucus.
3. reptiles characteristic of molt.
4. The ancestors of reptiles - amphibians.
5. Reptiles are more developed and refined the nervous and circulatory systems.
6. crocodiles, lizards, snakes and other species fertilization is internal.
7. Amphibians four spine, and five reptiles.This has similarities mammals and reptiles.
Interesting facts
most huge reptiles ever existed on Earth are the dinosaurs.They disappeared about 65 million years ago.They are inhabited by sea and land.Some species are able to fly.Currently, the most ancient reptiles are turtles.They are more than 300 million years.They existed in the era of dinosaurs.A little later came the first crocodiles and lizards (photo they can see in this article).Snakes also "only" 20 million years.This is a relatively youthful appearance.Although their origin is currently one of the greatest mysteries of biology.
