Asteroid, not volcanoes, made the Earth uninhabitable for dinosaurs, study finds
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Dinosaurs were wiped off the Earth by an asteroid, and not volcanic activity as some theories suggest, according to new research.
Most dinosaurs went extinct about 66 million years ago, and many scientists believe an asteroid crashing into the Earth killed them off.
However, some researchers have argued that a series of volcanic eruptions over tens of thousands of years led to their demise.
But a new study by scientists at Imperial College London, the University of Bristol and University College London suggests that only an asteroid could have fostered the conditions that caused dinosaurs’ extinction.
Artist’s impression of a dinosaur watching an asteroid hit the earth (PA)
The research also shows that a series of volcanoes could have helped life on Earth recover from the asteroid in the long term.
Lead researcher Dr Alessandro Chiarenza, who conducted this work while studying for his PhD at Imperial, said: “We show that the asteroid caused an impact winter for decades, and that these environmental effects decimated suitable environments for dinosaurs.
“In contrast, the effects of the intense volcanic eruptions were not strong enough to substantially disrupt global ecosystems.
“Our study confirms, for the first time quantitatively, that the only plausible explanation for the extinction is the impact winter that eradicated dinosaur habitats worldwide.”
Both an asteroid impact and long-running volcanoes would produce gases and particles that would block out light from the sun, causing permanent winters.
Researchers have previously used geological markers of climate and powerful mathematical models to try to work out whether asteroids or volcanoes were responsible for killing off dinosaurs.
But the new study combined this with environmental factors that different species of dinosaur needed to survive, like rainfall levels and temperature.
Scientists found that only an asteroid could have eliminated all habitable areas, whereas some potential habitats could have survived a volcano series.
Co-author Dr Philip Mannion, from University College London, added: “In this study we add a modelling approach to key geological and climate data that shows the devastating effect of the asteroid impact on global habitats. Essentially, it produces a blue screen of death for dinosaurs.”
University College London
University Of Bristol