Dinosaurs lived 150 million years ago. They were very interesting and dangerous animals. Dinosaurs were many species, like a Compsognathus, Tyrannosaurus, Velociraptor or a Pteranodon. They lived everywhere: all over the world except in Antarctica. Dinosaurs ate meat, fish, and small animals. Bigger dinosaurs, like a Tyrannosaurus, ate other big dinosaurs. Every species was very different. A Pteranodon was very small and light, with a very long beak. Compsognathus was small too, just 16 cm tall and 5.5 kilos weight. He was a very fast runner.A Velociraptor was strong, fast runner, he had a large claws. And the biggest dinosaurs-Tyrannosaurs were 6 meters tall and very heavy. He has a strong legs, long tail and very sharp teeth.
Now dinosaurs are disappeared (about 65 million years ago). Why they disappeared are three theories. I think, that the realest theory is this: climate changed a lot, because the continents were moving around. Summers got hotter, winters -colder. Dinosaurs had such big problems with these changes that they died.
In my opinion, that dinosaurs was appeared is good, because they are very dangerous not just for animals, but and for peoples.