Dinosaurs could have survived an asteroid strike that wiped them out had it taken place earlier or later in history, according to a new study released this week.
The study, which was conducted using up-to-date fossil records and improved analytical tools, has helped paleontologists learn more about the prehistoric creatures' demise, which took place some 66 million years ago.
They discovered that a few million years before the asteroid struck what is now Mexico, Earth was experiencing environmental upheaval. This included volcanic activity, varying temperatures, and changing sea levels.
During the time, dinosaurs' food chain was weakended by a lack of diversity among the large plant-eating dinosaurs on which other preyed, mainly due to changes in the environment and climate.
This allowed dinosaurs to become vulnerable and unlikely to survive the aftermath of the asteroid attack.
"The dinosaurs were victims of colossal bad luck. Not only did a giant asteroid strike, but it happened at the worst possible time, when their ecosystems were vulnerable. Our new findings help clarify one of the enduring mysteries of science," said Dr. Steve Brusatte, of the University of Edinburgh's School of GeoSciences, according to BBC News.
"It was a perfect storm of events that occurred when dinosaurs were at their most vulnerable," he added.
The impact caused tsunamis, earthquakes, wildfires, sudden temperature swings, and other environmental changes. As food chains disappeared, so did dinosaur species. The only dinosaurs to survive were those who could fly, which evolved to become the birds you see today.
The study suggests that had the asteroid struck a few million years earlier, when the range of dinosaur species was more diverse and food chains were more robust, or later, when new species had the chance to evolve, the could would have survived.
Paleontologists, led by the Universities of Edinburgh and Birmingham, ran the study of dinosaur fossils, mostly from North America, to analyze how dinosaurs changed over the few million years before the asteroid hit.
"Although our research suggests that dinosaur communities were particularly vulnerable at the time the asteroid hit, there is nothing to suggest that dinosaurs were doomed to extinction. Without that asteroid, the dinosaurs would probably still be here, and we very probably would not," said Dr Richard Butler of the School of Geography, Earth and Environmental Sciences at the University of Birmingham, according to the Guardian.
The study was published in the journal Biological Reviews.
"Although some types of dinosaurs were already declining in numbers before the famous asteroid impact, in most cases this impact was the smoking gun for the cause of the extinction," co-author Paul Barrett, of the British Natural History Museum, said to the Guardian. "This new work provides the best evidence for sudden dinosaur extinction and for tying this event to the asteroid impact rather than other possible causes such as the longer-term effects of the extensive volcanic activity that occurred at the end of the cretaceous."