Warm-blooded animals, they date from 233 million years ago

A study group led by Ricardo Araújo from the University of Lisbon and Romain David from the Natural History Museum in Paris testify to a new discovery. To give an essential evolutionary step, exactly the exams that were made on fossils found at the Karoo site in South Africa. The oldest, dating back to 233 million years ago, is said to be the earliest ancestors of mammals, namely the first warm-blooded animals. These are animals with their own heating. Frogs or snakes need to lie in the sun to warm up, while birds and mammals regulate their body temperature. A big plus, a warm body absorbs oxygen better.

It is about endothermy, the ability to warm up the body by monitoring its temperature. This has enabled the evolution of mammals that have adapted to any ecosystem. Until now, there has been great uncertainty in dating the exact appearance of this evolutionary discovery, but now this novelty opens up other time windows. The research has mainly focused on the mutations that have taken place over millions of years on structures in theinner ear. They are useful for equilibrium and are a good measure of the evolution of the endothermic capacity.

These structures change and have different idiosyncrasies depending on the type of animal. For example, in those with an internal temperature with large variations. Through this intuition, scientists have explored the numerous fossils in Karoo. A time window of 100 million years. Researchers going behind the inner ear canals have discovered the emergence of the first warm-blooded animals. They first appeared 30 million years before the primordial mammals. A very rapid appearance: in a million years.