Сочинение на тему морские черепахи

Sea turtles belong to the class of reptiles of the family of turtles. In nature, they appeared more than 220 million years ago. In total, 6 species of sea turtles are distinguished, which are combined into 4 species of the same family. Sea turtles inhabit mainly in the tropical seas and in the warm currents of the Atlantic, Pacific and Indian oceans. A characteristic feature of the structure of sea turtles is their horny or osteo-horny shell, which covers the main part of their body, performing the function of passive protection. The shell consists of strong dorsal and ventral shields, called carapace and plastron, respectively. Unlike their land relatives, sea turtles are deprived of the ability to drag the head and limbs into the shell. In addition, life in the water element transformed their limbs into peculiar fins, which are pronounced in large turtles and less in small ones, and in individual species, there are only swimming membranes between the fingers. The average life expectancy of sea turtles is 70-80 years.