The violent asteroid impact 66 million years ago might not have caused the extinction of dinosaurs if it had hit at a different time. Steve Brusatte, a paleontologist at the Edinburgh University blames the decline in biodiversity for their extinction. As he told The Guardian earlier, it was a loss of biodiversity that weakened the dinosaurs’ ecosystem and exacerbated the effect of tsunamis, earthquakes and devastation wrought by the asteroid collision.
"The decline made those ecosystems at the very end of the Cretaceous [period], when the asteroid hit, considerably more vulnerable to collapse than those ecosystems that existed even a few million years before," said Brusatte. "There is strong reason to believe that if the asteroid had hit a few million years earlier dinosaurs would have been better able to cope."
Brusatte was a part of an international team of scientists studying the possible causes of dinosaur extinction. In his report for Biological Reviews, he stated that while the dinosaurs were flourishing by the time of the collision, some large herbivores, like the horned triceratops, suffered a loss of biodiversity.
Dinosaur biodiversity in general suffered fluctuations during their 150 million years history on Earth, Brusatte told The Guardian. Taking that into consideration, the large herbivores might have had a chance to recover, and make the ecosystem more capable of withstanding the impact.
Steve Brusatte pointed out that the asteroid undoubtedly had a positive effect on the evolution. Without it, he told the newspaper, the dinosaurs would have had no reason to go extinct, thus depriving other species.