Dinosaurs

Scientists have found answers to the seemingly simple question, "Why the dinosaurs were so big?»
Researchers there are several theories. In the first, the active development of almost legendary creatures contributed to the warm climate, oxygen-enriched air, and vast areas to live (because then, scientists believe, all the land was united in the so-called Pangea). However, as a result of large-scale study of individuals who lived from 299 million to 100 thousand years ago, could not find the expected patterns of the category "climate-size».
The second theory relating to the strategy of competition between species. After all, small and big dinosaurs had to fight real hard, trying to survive, sometimes even when they belonged to the same species. At the same time, scientists have paid attention to the size of the eggs that lay dinosaurs. Their shell should pass the sun and the air, and thus also not be too thin to allow dinosaur fully develop before hatching. But not too hard shell created a perfect usloviy.

In general, the dinosaurs had to grow fast enough in the shell - and has hatched, only then they got the best chance of survival. Some types of dinosaurs "learned" to grow so quickly after birth, that the size of certain dinosaurs hatched young are 2500 times smaller than an adult dinosaur, however, this difference is quickly mastered. At the same time, adult dinosaurs laid eggs before they reach the maximum size: thus, the egg was quite comfortable home for the fetus, and dinosaur-parent, did it take a fast growing, in order not to lose in the evolutionary game ... their children.
Scientists also believe that after 65 million years ago a meteorite fell on the planet, too much difference in size in adults and kids could have caused the disappearance of species. However, this is only one possible model, which, moreover, criticized by some "colleagues in the shop" without finding it quite worth the argument. See also: Why did mammoths become extinct? On Earth, people lived giants. Why are the monkeys do not become a man? In China we have discovered a fundamentally new type of ancient man.

Source: facte.ru/pochemu-dinozavry-byli-bolshimi.html