The "superlungs" gave dinosaurs the energy they needed to run and fight: study

Beijing, October 25 According to one study, the bird 's lungs could give dinosaurs the energy needed to run and fight by providing a constant supply of oxygen.

In the oxygen-poor air of the Mesozoic era, nothing should have been fast, but Velociraptors could travel up to 64 kilometers an hour, researchers at the Chinese Academy of Sciences said .

Biologists have long known that birds, which descend from a branch of extinct dinosaurs, possess an unusual and sophisticated respiratory system that allows motorized flight.

However, palaeontologists wonder if these superlungs only appeared in birds or earlier in dinosaurs.

Unlike humans and other mammals, whose lungs dilate and swell, the lungs of birds are stiff, according to the study published in the journal Royal Society Open Science.

Special airbags located along the lungs lift heavy objects, pumping air through the lungs, where oxygen diffuses into the blood.

The lungs are attached to the vertebrae and ribs, which form the "ceiling" of the rib cage, helping to keep the lungs motionless.

A connector called a costo-cerebral joint, where the ribs and vertebrae meet, provides additional support.

This configuration allows a continuous flow of oxygen and requires less energy than the inflation and deflation of the lungs.

It also allows palaeontologists who study fossils to learn a lot about the lungs by examining the bones around them.

To find out when these superlungs evolved, paleobiologists from the University of Manchester in the United Kingdom and Louisiana State University in the United States turned to computer models.

They compared forms of skeletal elements such as vertebrae and ribs of various species of birds and non-avian dinosaurs.

Many dinosaurs, including therapies like Velociraptor and Spinosaurus, a large carnivorous dinosaur, had similar lung architecture to birds, the researchers said.

These dinosaurs sported a costo-cerebral joint and the bird-like "ceiling" of vertebrae and ribs that helps keep the lungs rigid.

All this suggests that dinosaurs had the same type of effective respiratory organs as birds, according to the study.

These superlungs could help explain why dinosaurs were able to dominate and spread, despite the thin air of the Mesozoic, researchers said.

At the time, the air contained only 10 to 15% oxygen, compared to 20% today, said the researchers.

The work highlights how the extraordinary lungs of birds evolved, said Jingmai O. Connor, paleontologist at the Chinese Academy of Sciences.

"The birds are really strange compared to all the other animals, they have this very advanced breathing system (and) we have always wondered:" How did it evolve? "Said O. Connor.

Now, it seems likely that the superlungs first developed in dinosaurs, then later, to support the powered flight of birds, she said.

However, O & # 39; Connor added that it is not because a fossil possesses the bone structure that lungs in the shape of birds resemble a lung.

Finding the lung tissue, which is almost never preserved, would be decisive, she said. SAR
SAR