What helps dinosaurs become

According to a recent study of American crocodiles, dinosaur lung evolution provides a competitive advantage between them with mammals.

Scientists have demonstrated that 'the effective method of respiration of birds is also used by modern American crocodiles - the common ancestor of dinosaurs -.

Cropped image of the side and back of the American crocodile

In mammals, their breath carries a lot of oxygen to the same pocket of the lungs, called alveoli. Air circulation through the alveoli transports oxygen into the bloodstream and removes carbon dioxide (CO ₂ ) emissions from the blood. But birds don't have alveoli, instead, the air will be blown directly into their cuffs. This adaptation allows the birds' lungs to retain clean air, allowing them to breathe at high altitudes, which can kill other animals.

To find out how the crocodile inhaled, scientists pumped gas through the lungs of a dead American alligator and directly measured the results of the airflow. The researchers found that similar to birds, air circulates through several layers of the trachea, ie, the injected gas only bounces back through the trachea before being discharged.

Competitive advantage for survival

With a similar respiratory method, birds, dinosaurs and American crocodiles are collectively known as Archosaurs, living in the Triassic period, 251-259 million years ago. During the early part of the Triassic period, oxygen levels in the atmosphere were lower than today.

"We all know in birds, the structure of the lungs is the cause of their good functioning," said lead researcher CG Farmer, a biochemical researcher at the University of Utah. in thin air ' . The above data have concluded that Archosaurs have a competitive advantage in survival in their 'Thin Air' world.

The high adaptation of dinosaurs could also explain why mammals exist so little until dinosaurs became extinct 65 million years ago. This is similar to the previous conclusions: these mammals are suppressed, and are quantitatively restricted by the Archosaurs.