Watch out, "Jurassic Park." A new study shows that dinosaurs might still be roaming the Earth if the asteroid that killed them had arrived at an earlier or later time in history. However, a rapidly changing climate and a shortage in the dinosaurs' food supply made them easy prey for the asteroid strike, which led to their extinction.
Scientists have often debated about what really killed the dinosaurs: we know that an asteroid wiped them out, but did other factors, such as volcanic activity and climate change, also play a part in their extinction?
After studying an updated database of fossil archives, an international team of paleontologists led by the University of Edinburgh discovered that just before the asteroid crashed into Earth 66 million years ago, the planet was experiencing some extreme environmental conditions, such as climate change that affected sea levels, along with a series of volcanic eruptions that occurred across the planet. These environmental factors created a lack of plant-eating dinosaurs, which affected the food chain of the carnivores that hunted and ate them.
The impact itself, which covered an area over six miles wide in what is now Mexico, also caused changing environmental conditions on Earth, creating earthquakes, tsunamis and drastic changes in temperature. Combined with existing conditions, this created a "perfect storm" that prevented the dinosaurs from surviving the asteroid's impact. Only dinosaurs that could fly survived extinction and they eventually evolved into birds.
So what would have happened if the asteroid had arrived earlier or later than it did? If the asteroid struck a few million years earlier, the dinosaur food supply would have been strong and the planet's environmental conditions stable. The impact would have still affected the dinosaurs, but they would have been more likely to survive.
The same is true if the asteroid happened a few million years later. In that scenario, evolution would have fixed the food chain problems, and the planet's environmental conditions would have evened out, creating a stronger survival rate for the creatures.
Of course, had dinosaurs survived the asteroid impact, it is probable that they, not humans, would be wandering the Earth.
"The dinosaurs were victims of colossal bad luck," Dr. Steve Brusatte, at the University of Edinburgh School of GeoSciences, said. "Not only did a giant asteroid strike, but it happened at the worst possible time, when their ecosystems were vulnerable."
The team of paleontologists will continue their studies, focusing on fossil records from Spain and China. They hope their studies will offer more insight into the exact events that created the dinosaurs' extinction.