Are such terrible dinosaurs as they are described? The word "dinosaur" means "terrible lizard." However, many of these animals did not look like lizards, and they did not at all resemble terrible ones. In the article we will talk about who the dinosaurs are, in what era they lived, how many years they roamed the earth and what is the life expectancy of these dinosaurs.
Who are dinosaurs?
Before touching on the question of how many years ago dinosaurs lived, let us clarify who they are at all. Dinosaurs are extinct terrestrial vertebrates. To date, scientists have about 500 different genera and more than 1000 different species.
Why were these vertebrates called dinosaurs? It happened in 1842. The term was introduced by the English biologist Richard Owen. This was done for the convenience of describing these species of extinct animals. The fact is that the bones of large vertebrates found by archaeologists in different places on the planet were gigantic in size. By this they astounded scientists. It was obvious that the creatures that lived many thousands of years ago on the planet were not just large, but huge. From the ancient Greek "dinosaur" - "scary, terrible."
Who was the first?
How many dinosaurs lived? We will find out a little later. In the meantime, it's time to find out whose remains were discovered very first. This is a stavricosaurus. A predator resembling a large dog in size. He weighed about 30 kg, this is with a height of 80 cm. The only difference from the dog is that the stavricosaurus moved only on its hind legs.
The second place belongs to the Herrerasaurus, or Errerasaurus. This is a two-legged “terrible lizard”, which is an order of magnitude larger than a stavricosaurus. It is a predator.
Habitat
How many dinosaurs lived and where? Their habitat was vast - the whole planet. The remains of the dinosaurs were found both in South America and in the territory of modern Egypt.
Classification
These vertebrates are conditionally divided into two types:
- Lizards.
- Poultry.
Why "conditionally", how do they differ? Direction of the bones. Lizard dinosaurs had pubic bones directed forward. Ptitsetazovye differed bones, directed back initially.
When did dinosaurs live?
We almost came to the main question of this article: how long did the dinosaur period drag on? These animals lived safely on the planet in the Mesozoic, namely from the late Triassic to the end of the Cretaceous. This is from about 225 million years ago to 66 million years.
How many dinosaurs lived
Let's take it. If we subtract 66 from 225, then we get 159. That is, it can be argued that the dinosaurs lived on our planet for almost 160 million years.
Differences not only in species
All the "terrible lizards" were completely different: predators and herbivores, small and large, two-legged and four-legged. The average life expectancy of dinosaurs of various species also varies. Small representatives lived very little, 20-30 years. Large individuals lived 2-3 centuries. It is known that large predatory dinosaurs reached puberty only by 40-50 years.
And how many years ago did dinosaurs live? They appeared about 225 million years ago.
Causes of extinction
Scientists are still arguing about this topic. It is very strange why such a number of rather large and well-adapted creatures died out. The hypothesis about this is quite a lot, the most common are the following:
- The fall of a giant meteorite to the ground.
- The split of the continents.
- Changing of the climate.
- The extermination of predatory species, first herbivores, and then their own kind.
Interesting Facts
How many dinosaurs lived? This we found out. Now, let's go over some very interesting facts about "terrible lizards":
- The largest of these was the seismazavr. This giant was distinguished by a calm disposition and the fact that he ate plant foods.
- The Titanosaurus is the hardest of all its "brethren." Its weight, according to scientists, reached 80 tons.
- In our world, lives the closest relative of vertebrates, extinct many thousands of years ago - a crocodile.
- Compsognathus is the smallest dinosaur representative. Its weight was about 2.5 kg.
- The tyrannosaurus is the most terrible predator of all dinosaurs that once inhabited our planet.
- Brachiosaurus are the longest representatives of all genera of dinosaurs. The body length of the brachiosaurus could well reach 50 meters.
- Huge and scary dinosaurs had a very small brain. The brain size of some individuals was no more than a walnut.
- The teeth of a tyrannosaurus reached 30 cm.
- Young tyrannosaurs daily added several kilograms during growth.
- The most protected was the ankylosaurus. On the tail was a bone club with sharp spikes. And on the body was spiked armor.
Summarize
The article examined questions about who dinosaurs are, how many years ago they lived, in what period, what is the life expectancy of a particular representative of the genus. Recall the main aspects.
Dinosaurs are vertebrates that died out many years ago. They appeared on the planet about 225 million years ago. How many dinosaurs lived? On earth, they lived about 160 million years. Life periods fell on the Mesozoic era. The largest dinosaurs successfully survived to the age of 200-300 years. As for small individuals, their age barely reached 30 years.
Conclusion
Dinosaur life is a mystery that scientists are still trying to discover. Perhaps someday they will be able to do this.