Dangerous Dinosaurs.
Dinosaurs were animals that lived millions and millions of years ago; we know about these dinosaurs because of their bones, or fossils you might say. Why did the dinosaurs died out? We don't know. One of the many theories is that a HUGE asteroid hit earth at a great speed and wiped out all the dinosaurs. Dinosaur periods. First was the Triassic period, about 245 to 208 million years ago. That was when the little dinos were around; like Coelophysis, Euparkeria, and Staurikosaurus. The second period was the Jurassic period, which was about 208 to 146 million years ago. During this period the dinosaurs started to flourish, the continents started to separate, and the climate began to change. That is also when the more dominant dinosaurs, like Brachiosaurus, Allosaurus, Apatosaurus, Diplodcus, and Stegosaurus were around. The last was the Cretaceous period, 146 to 65 million years ago, when Tyrannosaurus Rex, Parasaurolophus, Giganotosaurus, Triceratops, and Anatotitand ex...