Fate of the dinosaurs sealed even before asteroid impact

The number of dinosaur species in decline 50 million years before extinction and could have helped mammals take over.

18th April 2016
Fate of the dinosaurs sealed even before asteroid impact (© iStock)

A new study has dramatically changed the way we understand how dinosaurs died out.

Up until now, scientists believed that the meteorite that hit the Earth 66 million years ago set an abrupt end to their reign on our planet. But scientists at the University of Reading and the University of Bristol have discovered that 50 million years before the asteroid finally wiped them out, fewer species of dinosaur evolved than went extinct.

How do they know?

To reconstruct the pace of evolution by which older dinosaur species died out and new ones formed, the researchers combined data derived from fossils with a statistical analysis.

The results suggest that the total number of species declined in general and the number of some, like the long-necked dinosaurs, were dying out even quicker than the family of Tyrannosaurus rex.

"All the evidence shows that the dinosaurs, which had already been around, dominating terrestrial ecosystems for 150 million years, somehow lost the ability to speciate (evolve new species) fast enough,” says Mike Benton of the University of Bristol.

“This was likely to have contributed to their inability to recover from the environmental crisis caused by the [meteorite] impact."

The meteorite would have whirled up dust into the atmosphere, shielding the Earth from the Sun, cooling it down and changing the environment so heavily that the dinosaurs didn’t have a chance at survival.

What did it mean… to us?

One dinosaur’s tragedy is another mammal’s chance. When the reptile kings of the Earth started to diminish, they gave other species such as mammals the opportunity to develop. After the final extinction, mammals were ready to take over on our planet.

Time for a remake of The Land before Time based on those new facts…

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