Most of us are probably familiar with the idea that a meteor is responsible for causing a large extinction event millions of years ago that killed off the dinosaurs. Well, scientists are now claiming that it was all a matter of timing, and had that same meteor struck the Earth either a couple of million years before or after when it did, dinosaurs, as a species, may have been able to survive the event. 

According to CBS News, a team of scientists from around the world after scrutinizing the evidences for various "extinction scenarios" have determined that either a comet or asteroid was most likely responsible for the sudden extinction of the dinosaurs, approximately 66 million years ago. 

But according to researchers, the scenario that ultimately saw the dinos die out was more nuanced than we had previously postulated. Apparently, a "period of low diversity among herbivorous dinosaurs" in North America might have helped make the extinction possible. 

Stephen Brusatte from the University of Edinburgh stated regarding the global research team's new quest for answers, "The dinosaur extinction is one of the great mysteries in all of science. A group of us decided to come together and present a consensus." 

Brusatte and 10 additional dinosaur experts teamed up and examined some of the most recent discoveries in dinosaur fossils from North America from what is believed to be end of the Cretaceous Period (approximately 146 million to 66 million years ago).

The researchers agree that there is now no doubt that either a meteor or a comet is the most likely explanation for the dinosaurs' extinction.

They also agree that this occurred rapidly, with dinosaurs disappearing within "a few tens of thousands to hundreds of thousands of years, or even quicker," said Brusatte. 

It is still a mystery to researchers exactly why dinosaurs were naturally selected to die off after the meteor impact over other species, like mammals or birds for instance.

But the latest simulations and computer models seem to indicate that alterations to the planet's climate and landscape caused a reduction in the diversity of "plant-eating dinosaurs" in North America. Since these herbivorous dinosaurs comprised the bottom of the dinosaur food chain, when they began to disappear, it could have triggered a "domino effect" on the dinosaurs that relied on them for food, reports CBS. 

BAD TIMING?

According to Brusatte and his team, had the meteor in question struck the Earth just a few million years earlier or later --when a more diverse population of plant-eating dinosaurs roamed North America -- then the dinosaur extinction may not have happened; at least, not the way it did.  

Brusatte likened avoiding extinction during a low herbivorous dinosaur population to "limping across a road with a sprained ankle" and trying not to get hit by a bus. With the bum ankle--if you will--"you're more likely to get run over," he stated. 

Yet there is still some uncertainty with this propose model, as the data is limited to fossils from North America.

Scientists are currently unable to demonstrate whether the rest of the world's herbivorous dino population reflected the same dwindling numbers as their North American counterparts. 

"I think dinosaurs are a cautionary tale," Brusatte stated. "When you mess with diversity, you can be even more susceptible to a knockout blow."