A 30-year-old theory about the demise of the dinosaurs gets affirmation from a team of scientists.
- A group of 41 geologists, paleontologists and other researchers conclude that a big asteroid wiped out the dinosaurs.
- The theory was first posited in 1980 but has since faced opposing theories.
- Among the leading alternative theories is that volcanic eruptions may have played major roles.
An all-star panel of researchers says it was the crash of a giant asteroid that killed off the dinosaurs.
Think you've heard that before? You're right.
In 1980, Louis Alvarez and his son Walter published a paper blaming the dinosaur extinction 65 million years ago on an asteroid impact. The probable crater was later found at Chicxulub, Mexico, and the idea gained wide scientific acceptance.
In the past few years, however, suggestions were made that the demise of the dinosaurs might have been caused by the eruption of volcanoes, known as the Deccan Traps, in India, or multiple asteroid impacts.
That prompted 41 geologists, paleontologists and other researchers to come together to review the data.
Their conclusion, published in Friday's edition of the journal Science: It was a giant asteroid striking Chicxulub that blasted a cloud around the world that led to the end of the dinosaurs.
The argument for multiple impacts isn't supported by worldwide data, and the Deccan eruptions actually began 400,000 years before the end of the dinosaurs, Kirk Johnson of the Denver Museum of Nature and Science said.