Reptiles in the majority are land animals. They were called so on their way of movement: reptiles adjoin all over to the earth and drag themselves ("kowtow").
What morphological features of reptilesReptiles have the dry, covered with horn scales skin. They usually have no skin glands. Heart of these animals three-chambered, consisting of two auricles and a ventricle, and only at crocodiles – four-chamber.
The blood circulatory system of reptiles is presented by two circles, but their body temperature is changeable and depends on environmental conditions. The brain of reptiles is arranged more difficult, than at Amphibia.
Reptiles – diclinous animals, fertilization at them internal. The most part of reptiles breeds an otkladka of oosperms: at lizards and snakes they are covered with a leathery cover, at turtles and crocodiles – a limy shell. Also viviparous types occur among reptiles.
The majority of reptiles – insectivorous or predators. Land turtles eat plants.
Eliminative organs of reptiles are kidneys. Reptiles by means of the lungs having the cellular building breathe. As outside these animals are covered with skin, dry and horny, not capable to breath, lungs at them are the only respiratory organ, unlike amphibians. The cellular building increases the respiratory surface of lungs.
The cellular structure of lungs allowed reptiles to adapt to life on the land. Skin breath is observed only at sea serpents and spineless turtles.
From what ancestors there were modern reptilesReptiles came from ancient reptiles – the kotilozavr living on Earth about 285 million years ago. In the building they kept the signs inherent in the most ancient Amphibia having a tail – to stegotsefala. The peak of blossoming of reptiles had for 70 to 255 million years ago: on the land there lived dinosaurs, in water – ichthyosauruses, in air – pterosaurs. The global cold snap which happened on the planet about 100 million years ago led to mass extinction of reptiles. Modern reptiles there are about 7 thousand types united in 4 groups: Scaly, Crocodiles, Turtles and Rhynchocephalia. To Scaly carry lizards, agamas, snakes, geckoes and chameleons. It is the most numerous and various group of reptiles. Among turtles there are overland, sea and freshwater types, but the body of all from them is hidden under a massive armor. Crocodiles (their only 26 types) are considered as the most high-organized group of reptiles, and modern representatives of Rhynchocephalia are the gatteriya inhabiting islands of New Zealand.