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Dinosaurs on the verge of extinction before asteroid hit Earth: study

It is tempting to ponder how life on Earth may have been shaped like an untouched space rock 66 million years ago. Such an impact in present-day Mexico killed most dinosaurs and terrestrial and aquatic animals. Without it, humans and Will other mammals duke it out with T. rex and triceratops?

The answer may not be, according to a study published Tuesday.

The research found that six large groups of dinosaurs were gradually Extinct 10 million years before the collision. The consequences of the impact were a 1 mile high tsunami, raging fires. and dense clouds of dust and sulfur that obscured the sunlight. It’s just a nail in the dinosaur’s coffin.

“Meteorites were seen as a coup for dinosaurs. That̵

7;s done,” Fabien Condamine, a research scientist at the University of Montpellier in France who co-authored the new study, told Insider.

Condamine and collaborators suggest that global cooling may have reduced overall dinosaur numbers. This made it impossible for animals to recover after a catastrophic event.

“Many paleontologists think dinosaurs could survive if the asteroid didn’t hit Earth. Our study brings new information to this question. And it doesn’t seem like the dinosaurs were in good shape before the crash,” Condamine said.

The dinosaurs are leaving.

t rex

An adult Tyrannosaurus rex weighs between 6 and 9 tons and can grow to 43 feet long.

Illustration by Zhao Chuang/Courtesy of PNSO

The researchers behind the new study looked at 1,600 fossils from 247 species of dinosaurs that lived in the Late Cretaceous, from about 100 million to 66 million years ago. such as T. rex, triceratops, and platypuses.

The team grouped them into six large families. It then analyzes how the diversity of species in those families has changed over time. The results showed that in all six groups, the number of species began to decline 76 million years ago, before the impact of the space rock.

Condamine said: “We did not find dinosaurs as highly diverse and diverse in the late Cretaceous as previously thought.

He is not the first scientist to suggest that dinosaurs gradually gradually extinct A 2016 study found that while different dinosaur species that used to live on Earth have long been extinct. There was no new species to replace them. The question remains, though, whether that conclusion is merely a product of an incomplete fossil record. But this new study shows that older species actually have a higher rate of extinction than younger species.

herbivore monopoly

Arctic Dinosaur Hadrosaur

A painting of Ugrunaaluk kuukpikensis, a species of duck-billed dinosaur that lived during the Cretaceous period.

James Havens

in the late Cretaceous The planet began to cool. 80 million years ago, Earth’s temperature dropped about 13 degrees Fahrenheit (7 degrees Celsius).

Because dinosaurs relied on environmental temperatures to regulate their body heat, Condamine said climate change could affect extinction rates.

The study author wrote: “The warm period favored dinosaur diversity, while the cooler period led to increased extinction.”

Another possible explanation for the decline of dinosaurs is a change in the number of herbivore species in the ecosystem. Hadrosaurs, or platypuses It appears to dominate between 76 million and 66 million years ago, competing with leaf-eaters like tyceratops and armored ankylosaws. That contributes to the decline in other herbivores.

“Eliminating herbivores will make entire ecosystems more prone to extinction,” Condamine said.

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