History holds many mysteries and we cannot know everything, but everything we learn is interesting. Dinosaurs have a deep history, they reigned on Earth for more than 160 million years, from the Triassic period about 225 million years ago to the end of the Cretaceous period about 65 million years ago. Today scientists can recreate the appearance of these animals, their lifestyle and habits, but many questions have not yet been answered. And yet comes the question of how in general appeared dinosaurs and why they disappeared? Let's try to find out in order.

Why the name ‘Dinosaurs’?

When translated from Greek, the term ‘dinosaur’ means ‘terrifying’ or ‘fearsome lizard’. This name was introduced by British explorer Richard Owen in 1842. It was his idea to call the first discovered fossilized remains of ancient lizards to emphasize their unprecedented size and grandeur.

The Age of Dinosaurs

The time in which dinosaurs lived is called the Mesozoic Era, which includes three periods: Triassic, Jurassic and Cretaceous. The Mesozoic Era began about 225 million years ago and ended about 70 million years ago. Dinosaurs began to develop history in the Triassic period, but they became more widespread in the Cretaceous period. Long before dinosaurs, there were reptiles living on the planet. They resembled the lizards that modern humans are accustomed to in that their paws were on the sides of their bodies. But when global warming began 300 million years ago, there was an evolutionary explosion among them. All the reptile groups began to evolve. The Archosaurs appeared - it differed from its predecessors in that its paws were located under the body. Presumably, it is to this chronological interval that the emergence of dinosaurs belongs.

Dinosaurs of the Triassic period

Already at the very beginning of the Triassic period, many new species of lizard appeared. It is thought that they were already travelling on two legs, because their front legs were shorter and much less developed than their hind legs. This is how they differed from their predecessors. The history of the origin of dinosaurs says that one of the first species was Stauricosaurus. It lived about 230 million years ago in what is now Brazil.

During the Triassic period, there were already a large number of other reptiles such as saurians, cynodonts, ornithozuchids and others, so the dinosaurs had to endure a long competition before they could occupy their niche and flourish.

Jurassic Period

By the beginning of the Jurassic period, dinosaurs had become full-fledged inhabitants of the planet. They settled all over the Earth's surface: in mountains and plains, swamps and lakes. The history of dinosaurs of this period is marked by the appearance and spread of numerous new species. Allosaurus, Diplodocus, Stegosaurus are examples. And all these lizards differed from each other in size, appearance and had a different way of life. Some dinosaurs were predators, others were harmless and herbivorous. In this period, winged lizards appeared and they were called pterosaurs. Reptiles reigned in the oceans on land and in the sky.

Cretaceous Period

During the Cretaceous period, the number and diversity of dinosaurs reached a maximum level. On the other hand, some scientists do not share the view of a sudden and significant increase in the number of reptiles. In their opinion, representatives of the Triassic and Jurassic periods are much less studied than the inhabitants of the Cretaceous. At this time, a lot of herbivorous inhabitants developed, this is due to the fact that on the planet appeared a lot of new plants, but there were also a lot of predators. It is to the Cretaceous period refers to the emergence of such a famous species as Tyrannosaurus. By the way, it turned out to be perhaps one of the most famous dinosaurs. The most massive of all carnivorous reptiles, he weighed up to eight tones, and his height could reach 12 meters. The Cretaceous period also saw the appearance of such famous species as Iguanodon and Triceratops.

The demise of the dinosaurs

Dinosaurs disappeared about 65 million years ago. Their demise occurred at the end of the Cretaceous period, scientists have many guesses about their deaths, but there is no definitive one. Scientists can't guess whether they died quickly or slowly. What is known is that it was one part of the great extinction of that time. Not only dinosaurs, but also other reptiles, mollusks and some algae disappeared from the face of the Earth. Some scientists believe that it was triggered by the fall of an asteroid after which a cloud of dust rose into the sky, covering the sun for months. Other scientists think it was a change in temperature and another theory is that a star burst into flames causing the planet to be covered in deadly radiation.