Name: If An Asteroid Didn’t Kill All The Dinosaurs, What Did?
Uploaded: 2021-04-27T03:43:49.000Z
Duration: 3 min 23 s
Description: Thousands of YouTube videos with English-Chinese subtitles! Now you can learn to understand native speakers, expand your vocabulary, and improve your pronunciation...

When I was in grade school, my teacher taught me that about 66 million years ago a huge

asteroid hit the earth right around Mexico and BAAAM.

Just like that - wiped out the dinosaurs.

Hello survivors, Lissette here for DNews.

The mass extinction that doomed the dinosaurs is still a bit of a mystery.

As with anything that happened millions of years ago, we must rely on indirect evidence

to test theories about things that we can no longer directly observe or record.

So there are lots of theories about how the dinosaurs died off.

But one thing scientists are increasingly agreeing on is that the dinosaurs did NOT

Nope, instead they died a slow, miserable, gradual death.

It wasn't just the asteroid that killed them.

Though it definitely played a part, there were many other factors involved.

Scientists in the UK at the University of Reading and the University of Bristol think

they actually started slowly dying out about 40 million years before the asteroid hit;

And then, after the blast, continued to die off for millions of years after.

Sure, they agree with most of our teachers that the asteroid at Chikshuhloob Mexico did

indeed kill many dinosaurs through direct impact and through the tsunami it triggered.

But, they argue that this was more like the straw that broke the camel's back.

During the Cretaceous period, before the asteroid hit, the earth was experiencing global environmental

changes that did not favor land roaming dinosaurs.

It was experiencing sea level fluctuations, a period of extreme cooling, and lots of volcanic

This meant that dinosaurs had to move around to find food and resources where the climate

But, it was difficult for dinos that roamed on foot because during the course of the Cretaceous

period, the land itself was slowly breaking up from one large continent to many different

Things were a little better for birds who could fly to places with resources, but even

On top of that, mammals were on the rise before the asteroid - it turned out pretty good for

But, scientists theorize that our small rodent looking relatives likely helped to knock dinosaurs

They may have competed with the dinosaurs for food and other resources, eaten their

Altogether this meant that when the asteroid did hit 66 million years ago, the dinosaurs

The dwindling populations could not reproduce quickly enough to survive the losses from

the asteroid's impact, the tsunami and other environmental changes that ensued.

Between that, the volcanoes, the fluctuating oceans, and the global cooling (not great

for cold-blooded reptiles) - the dinos didn't stand a chance.

The asteroid certainly had an impact, but the dinosaurs had been dying millions of years

before it, and continued to die off millions of years afterward.

But for more on which dinos actually survived the mass extinction.

What do you remember being taught about the dinosaurs?

Did your teachers tell you the same thing I was told about their extinction?

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If An Asteroid Didn’t Kill All The Dinosaurs, What Did?

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