Gradually, in the Mesozoic, many species formed among the reptiles. The appearance of giant reptiles is especially characteristic for this time. So, some dinosaurs (“terrible lizards”) were up to 30 meters long and weighing up to 50 tons – the largest of the land vertebrates that ever existed on Earth. Such giants were even forced to return again to a semi-aquatic way of life – in water their mass decreases. They wandered through the shallow waters and ate coastal and aquatic plants, pulling them out with the help of a long neck. There were then predators, also very large, up to 10 meters long. Some reptiles who lived then even returned completely to an aquatic lifestyle, although they did not lose pulmonary breathing. Such, for example, was an ichthyosaur, or a fish hunter, in shape very similar to a modern dolphin. Finally, there were flying dinosaurs – pterodactyls.
Thus, reptiles have mastered all habitats – terrestrial, water and air. They formed many species and became the dominant animals on Earth.
But 70-90 million years ago, the climate in most of the Earth changed dramatically, became cold. At the same time, there were more diverse species of warm-blooded mammals – competitors of reptiles. This led to the fact that most reptiles, primarily all giant forms, became extinct, since giants cannot hide in shelters for the winter.
To this day, few reptiles have survived – turtles, crocodiles, lizards and snakes. By the way, among them the largest are found only in warm countries and lead an aquatic or semi-aquatic lifestyle.