• Every school child knows the dinosaurs were killed off by an asteroid smashing into the Earth some 66 million years ago.
  • But scientists say the story may not be quite that simple, and that massive volcanic eruptions over hundreds of thousands of years may have contributed to the dinosaurs’ demise at the end of the Cretaceous period.
  • Before the 1980s, the dominant theory had been that huge and prolonged volcanic eruptions caused a rapid and deadly shift in the planet’s climate by sending vast clouds of ash, gas and dust into the atmosphere.
  • Then scientists discovered the huge Chicxulub crater of an ancient asteroid impact off the Caribbean coast of Mexico, which they posited had sent so much debris into the atmosphere that it hampered photosynthesis in plants and killed off three-quarters of life on Earth.