In the first part of Jurassic Park there was a scene that was heavily criticized by scientists: a dinosaur opened its big mouth in front of a mirror and its terrifying breath was shown in the glass, something impossible in a cold-blooded animal.

Now we can say that that scene was not a mistake.

Advertisement

The first great undisputed enigma of dinosaurs is their extinction. Even today, articles continue to be published trying to give an answer to why they disappeared forever. The last hypothesis is that they were already “mortally wounded” as a species before the meteorite and affected by the climate changes that have already been verified. But, as we promised in the title, what now seems to have an answer is the second great riddle of dinosaurs: were they warm-blooded?

reptiles or birds

The blood of modern reptiles is cold, but the blood of modern birds is warm, like mammals, like ours. So where do dinosaurs fit in?

A new study of the thigh bones of Plesiosaurus, Stegosaurus, Diplodocus and Allosaurus compared to those of modern hummingbirds posits that the extinct animals were warm-blooded.

Advertisement

So fearsome predators like T. rex and telescopic-necked dinosaurs like Brachiosaurus were warm-blooded creatures in the same way as birds and mammals, according to a groundbreaking new study published in the scientific journal. Nature.

By visualizing the bones with infrared spectroscopy, the scientists found a large number of molecules produced as waste during oxygen inhalation, they report in Nature.

The molecules are a sure sign of a high-powered metabolism that warm-blooded animals use to keep their body temperature constant, they say.

Advertisement

If they were warm blooded they could survive the meteorite

Previous hypotheses suggested that dinosaurs could not survive the aftermath of the asteroid that hit Earth 66 million years ago due to their low metabolism; the new study supports this premise, say the authors.

“This is really exciting for us as paleontologists – the question of whether dinosaurs were warm-blooded or cold-blooded is one of the oldest questions in paleontology, and we now think we have a consensus that most dinosaurs were warm-blooded. ” explains the study’s lead author, Jasmina Wiemann, a postdoctoral researcher at the California Institute of Technology, in a press release.

Advertisement

They were more like birds than reptiles

Previous generations of paleontologists had confused dinosaurs with reptiles, leading to assumptions of a reptilian appearance and lifestyle. Today, most paleontologists agree that dinosaurs were much more bird-like after the discovery in the 1990s of feathered fossils, which led to the understanding that modern birds are direct descendants of dinosaurs.

It has been proposed that having a high metabolic rate is one of the reasons birds survived the mass extinction that wiped out the dinosaurs 66 million years ago. However, Wiemann said this study indicated this was not true: many dinosaurs with exceptional bird-like metabolic abilities went extinct.

Advertisement