Has scaly and hard skin, crocodiles located in the tropical areas of Africa, America, Asia and Australia appeared for the first time on the planet during the Eocene, a geological time scale that began about 56 million years ago and ended about 34 million years ago.

Crocodiles appeared at about the same time as dinosaurs. When a catastrophe wiped out most of these animals at the end of the Triassic, some crocodiles were able to survive, eventually living in rivers and swamps.

Also, about 65 million years ago, many species of these reptiles, often referred to as “the last living dinosaurs”, survived when an asteroid wiped out most of life at the time. Many scientists say that the reason crocodiles stay alive has to do with their ability to leave for long periods of time without eating and because of their cold blood.

A new study conducted in January in the UK explains how a evolutionary pattern “start and stop”.governed by environmental change, may explain why crocodilians have had little change since the age of dinosaurs.

crocodiles today they look a lot like those from the Jurassic period about 200 million years ago. there is also very few living species now: only 25. Other animals, such as lizards and birds, have achieved diversity of thousands of species in the same duration or less.

Prehistory has also seen crocodile species we do not see today, including giants the size of dinosaurs, herbivores, fast runners, and serpentine forms that live in the sea.

In new research published in the journal Biology of Nature Communicationscientists explain how crocodiles follow a pattern of evolution known as “punctuated equilibrium”.

The speed of their evolution is generally slow, but sometimes they change faster because the environment has changed. In particular, this new research suggests that their evolution accelerates when the weather is warmer and their bodies grow.

The lead author, Dr. Max Stockdale from the University of Bristol’s School of Geographic Sciences, said in a statement: “Our analysis used a machine learning algorithm to estimate the rates of evolution. rate of evolution is volume change which occurred over a certain period of time which we can calculate by comparing the dimensions of the fossils and taking into account their age ”.

And he detailed: “For our study, we measured body size, which is important because it interacts with how fast the animals grow, the amount of food they need, the size of their population and the chances are they will be exhausted. “

The findings show that the limited diversity of crocodilians and their apparent lack of evolution are the result of a slow rate of evolution. The crocodiles allegedly reached a body plan This is efficient and versatile enough they no longer have to change it to survive.

This versatility may be an explanation for why crocodiles survived the meteor impact at the end of Cretaceous period, where dinosaurs died. Crocodiles generally thrive best in warm conditions because they cannot control their body temperature and require heat from the environment.

The climate during the time of the dinosaurs was warmer than it is today, and that may explain why there are many more different crocodiles. what we see today. Having the ability to take energy from the sun means they don’t have to eat as much as a warm-blooded animal like a bird or mammal.

Stockdale added: “It’s exciting to see that there is a complex relationship between the land and the living things we share. Crocodiles have come up with a way of life that is versatile to adapt to the major environmental changes that have taken place. From back then, when dinosaurs were around. “

The next step in the team’s investigation was to find out why some species of prehistoric crocodiles became extinct and others did not.