What are the morphological features of reptiles
reptiles have dry, covered with horns flake skin. They usually do not have skin glands. The heart of these animals is three-chambered, consisting of two atrials and a ventricle, and only in crocodiles — four-chambered.
The circulatory system of reptiles is represented by two circles, but their body temperature is fickle and depends on environmental conditions. The brain of reptiles is more complicated than that of amphibians.
Reptiles are separated animals, fertilization in them internal. Most reptiles are propagated by laying fertilized eggs: in lizards and snakes they are covered with leathery sheath, in turtles and crocodiles – calcareous shell. Also found among reptiles are live species.
Most reptiles are insectivores or predators. Terrestrial turtles feed on plants.
Removal organs of reptiles — kidneys. Reptiles breathe with the help of lungs having a cellular structure. Since the outside these animals are covered with dry and incapable skin, their lungs are the only breathing organ, unlike amphibians. Cellular structure increases the respiratory surface of the lungs. The
cellular structure of the lungs allowed reptiles to adjust to life on land. Skin breathing is observed only in sea snakes and soft-bodied turtles.
From which ancestors descended modern reptiles
reptiles came from ancient reptiles — cotylosaurs that lived on Earth about 285 million years ago. In their structure they retained the characteristics inherent in the oldest tailed amphibians — stegocephales. The peak of reptiles came from 70 to 255 million years ago: on land lived dinosaurs, in water – ichthyosaurs, in air – pterosaurs.
A global cold snap that occurred on the planet about 100 million years ago led to a mass extinction of reptiles. Modern reptiles are about 7 thousand species, united in 4 units: Scale, Crocodiles, Turtles and Beak heads.
The scaly includes lizards, agams, snakes, geccons and chameleons. It is the most numerous and diverse squad of reptiles. There are terrestrial, marine and freshwater species among the turtles, but the body of all of them is hidden under a massive guesthouse. The most highly organised detachment of reptiles are considered to be crocodiles (there are only 26 species), and modern representatives of the Beanheads are the gatterias that inhabit the islands of New Zealand.