According to scientists, the immediate recent family of crocodiles who appeared more than 250 million years ago are birds. It is difficult to believe in it, however if the nobility as these dangerous predators breed, a lot of things become clear.
Green and dangerous: as there live crocodilesCrocodiles are extended practically to territories of all tropical countries now. These reptiles prefer to live in reservoirs with fresh water. Also some species of crocodiles are known, for example, Nile and African uzkoryly which can quite live also on the sea coast, that is they are not frightened by salty water. According to scientists, in ancient times crocodiles in general lived mainly on the land, only later they gradually passed to water life. Now they can spend the most part of days in water, only sometimes getting out to the land to get warm in the sun.
Features of reproduction
Females of crocodiles breed, laying from 20 to 100 eggs in sand. Usually the laying is hidden on a shallow, sometimes eggs bury in the peculiar nest created by means of liquid dirt and the decaying leaves. How many eggs are in a laying - depend on the sizes and a type of an individual.
Now practically all crocodiles prefer to live in water or about reservoirs, however in the territory of South America also completely overland animals belonging to the Mesosuchia group lived.
If the female of a crocodile chose the shady place for a laying, she will not really deeply whereas in solar she can dig out about 50 dig a pole. Having covered eggs with earth, mixed with a grass and foliage, the female as a rule does not depart far from the laying and guards future cubs. According to scientists, all crocodile eggs usually hatch at once, and temperature conditions of an incubation period influence sex of offspring. For example, when crocodile egg is stored at a temperature of 31-32 °C, from it the male will hatch if level was lower or higher, females will be born.
Scientists managed to record on video that some individuals of this species of reptiles are capable even to get of the trees growing near the river where they live.
Care of posterity
It is interesting that little crocodiles begin to make the first characteristic croaking sounds, still being in egg. Mother is krokodilit, having heard this signal, begins to dig out at once a laying to help cubs to be chosen the. Then the female tries to transfer krokodilit in water, accurately taking them in a mouth - despite a set of sharp teeth, this process is quite safe for kids as mother in a mouth has baroretseptor. Thanks to them, the female can well feel what occurs in her mouth. According to zoologists who study reproduction of crocodiles, females, transferring to water of the cubs, more than once selected and also carried away in water and accidentally got little turtles. It is known that some species of turtles seek to lay eggs about crocodile layings to ensure safety to future posterity.