The first dinosaurs appeared on the stage of the Earth's history 230 million years ago. Our knowledge of them stems primarily from bone and fossil finds, used by scientists since the mid-19th century to reconstruct their shape. In contrast to popular opinion, which associates dinosaurs principally with the dragons and mythical beasts of fairy tales, we now know that this species was distinguished by an enormous generic variety. The smallest member of this animal family was scarcely bigger than a chick; the largest representative weighed the equivalent of ten elephants.
Yet it is precisely the largest specimens which one should imagine as peace-loving herbivores, spending the entire day eating so as to still their voracious appetite. Moreover, their dimensions were such as to make it hardly praticable for them to go in search of prey. They were far too slow to engage in hunting.
"Dinosaurius" - which means something like " terrifyng lizard" - would thus appear to refer more to their size than to any danger they might have constituted. What can be said today with certainty is that these monstrous creatures died out some 65 million years ago.
However, the reason behind the dinosaurs' extinction - dramatic climatic variation, or a change in the plant world serving the creatures as their source of food - will in all like-lihood remain for ever unresolved.