Dinosaurs were reptiles that lived more than 60 million years ago on Earth, and that had it under their control for more than 135 million years. Its exact origins still remain unknown; however, it has been determined that they may have arisen 230 million years ago. They achieved an early diversity that, until now, is also the subject of extensive studies. The term “dinosaur”, originates from “δεινός” (deinos, terrible) and “σαῦρος” (sauros, lizard), thus being “terrible lizards”. These lived until the end of the Cretaceous, when a mass extinction wiped out much of the species in this group from Earth.
More than five hundred genera and a thousand species of dinosaurs have been counted, from whose characteristics the knowledge of their continental evolution is extracted. These could be both herbivores and carnivores; the oldest specimens indicate that they were originally bipedal, but quadruped species were also found. They had large ridges on their heads, as well as bony structures that, in certain species, could serve as armor; its size could go from 50cm to 9.5 meters in height. In addition to the land dinosaurs, there were also the avian dinosaurs, from which the birds that are known today evolved.
In addition, it should be noted that, despite classifying them as reptiles, they are far from having the same characteristics and behavior as them; in fact, it is claimed that, contrary to popular belief, dinosaurs were not cold- blooded animals, they had fast metabolism and were endowed with excellent social skills. The causes of its extinction are not yet clear; however, the theory that a meteorite impacted the Earth and, as a consequence, temperatures may have dropped (another version suggests that an unusual heat wave hit the planet), complicating the development of normal life.
