An international panel of 41 scientists reviewed some 20 years of research and has determined that the only plausible explanation for the extinction of all the dinosaurs had to be a giant asteroid slamming into the Earth. The panel released their findings on Thursday, March 4, 2010.
Scientifically, the cause is called Cretaceous-Tertiary (KT) extinction. The theory maintains that around 65 million years ago a gigantic strike caused a hellish environment, whipping out the ecosystem and the dinosaurs at the same time.
Some scientist have held that volcanic activity in the Deccan Traps – now India – caused the extreme climate change after a series of super volcanic eruptions that lasted more than 1.5 million years.
The respectable journal Science published the new study, conducted by scientists from Europe, the United States, Mexico, Canada and Japan. The study found that a 15-kilometer (9 miles) wide asteroid slammed into Earth at Chicxulub in what is now Mexico.
"We now have great confidence that an asteroid was the cause of the KT extinction. This triggered large-scale fires, earthquakes measuring more than 10 on the Richter scale, and continental landslides, which created tsunamis," said Joanna Morgan of Imperial College London, a co-author of the review.
The scientist estimated that the asteroid struck Earth with a force a billion times more powerful than the atomic bomb at Hiroshima.
Morgan said the "final nail in the coffin for the dinosaurs" came when blasted material flew into the atmosphere, shrouding the planet in darkness, causing a global winter and "killing off many species that couldn't adapt to this hellish environment."
The research included analyzing the work of paleontologists, geochemists, climate modelers, geophysicists and sedimentologists who have been collecting evidence about the KT extinction over the last 20 years.
Peter Schulte of the University of Erlangen in Germany, a lead author on the study, said fossil records clearly show a mass extinction about 65.5 million years ago -- a time now known as the K-Pg boundary.
"The KT extinction was a pivotal moment in Earth's history, which ultimately paved the way for humans to become the dominant species on Earth," Gareth Collins of Imperial College wrote in a commentary on the study.