75% of life on Earth win extinct, including a dominant group of animals that has come to mesmerize our attention.

The diversity that we see in dinosaurs is really a reflection off how successful they were.

Meat Nat Geo Explorer Diego Pol, one of the paleontologist who discovered the largest dinosaur ever.

Dinosaurs were predominant in our world for over 100 and 40 million years.

Humans have bean in this planet for 200,000 years on.

There's no many cases in the history of our planet that one group, it's so predominant and so successful for such a long time.

Humans and dinosaurs didn't overlap, not even close.

Let's go, Tyrone.

And as we've seen in Hollywood, Way can be thankful for that.

But dinosaur fossils left humans wondering.

Where'd they go?

Dinosaur extinction has Bean a fascinating topic for a long, long time.

We see their presence up to 66 million years old, and then after that there's nothing.

They're gone throughout the 20th century There were, Ah, lot of arguments, theories very dramatically from the somewhat plausible to the downright bizarre.

Some pointed out of control hormones or cataracts.

Others blamed a world taken over by hungry caterpillars.

The answers eluded experts until 1980 when two scientists working here discovered a clue.

The link to it being an asteroid impact started almost by accident.

Walter Alvarez and his father, Louis Alvarez, were actually very interested in a place called Rubio, Italy.

There were lime stones that were Cretaceous, and then there were lime stones that were after the mutations what we call the Paleo gene, and that the extinction event was writing that boundary.

Instead of finding anything sort of background normal, they actually found a spike in something called a radio.

Iridium is a surprise because we have very little or idiom present on the surface of the earth versus what the asteroids are made of.

Walter and Louis Alvarez co authored a groundbreaking paper hypothesizing that an asteroid was responsible for the mass extinction.

But that in itself raised another question.

Where's the crater?

Scientists have further into the layer of iridium for answers?

The real key clue was, while it's only a centimeter thick layer and most of the world.

As you approach the Gulf of Mexico, that layer becomes much, much thicker.

We start seeing layers that are a meter thick or even hundreds of meters places as you get closer and closer to the place where the impact happens.

By the early nineties, the science was becoming more convincing more than 3000 ft below the surface of the Yucatan Peninsula.

Latest saucer shaped structure different from volcanic terrain This was the chicks loob crater.

So to answer the fundamental questions about how this particular impact caused a mass extinction event way needed to drill into it.

Where it actually hit was lime stones.

So calcium carbonate, which makes a lot of CO two when you vaporize it.

But even more important, perhaps, where the bath rights thes are rocks that are high in sulfur.

And so when those get vaporized, they actually put native sulfur into the atmosphere, which, when combined with water, becomes sulfate aerosols, which is a pollutant that actually succeeds in cooling the planet off.

If it had happened a little bit earlier or a little bit later, in terms of the rotation of the earth.

It could have easily hit the Atlantic Ocean or the Pacific Ocean and entirely missed this shelf environment with all these sediments beneath it.

And if it had done that, most of the material that would have been rejected would be the a prized asteroid and just water where it hit and with the energy it hit, seemed to have had the right recipe to create a global catastrophe.

Dinosaurs were likely living in a vulnerable time leading up to the asteroid, but perhaps more surprising eyes the realization that not all dinosaurs went extinct.

So most people think that dinosaurs are extinct.

But this is completely false because, you know, if you look out your window, you're going to see a living dinosaur, a za vertebrate paleontologists.

My specialty is understanding how birds evolved from dinosaurs and then also how the earliest birds evolved into what we would consider.

Ah, bird.

Today you have this huge diversity of dinosaur AEA, and then you have one group that's called the Thera Pota, and everybody knows Thera pods that includes famous members like Velociraptor or T rex.

But one group of thera pods eventually gave way to birds.

This'll resilient group of Thera pods is represented today by over 10,000 living species of birds.

Modern birds is the most diverse played of vertebrates living on land on the planet today.

So people are always saying that, like this is the age of the mammals always like to joke and be like it's still the age of the dinosaurs.

While the dinosaur extinction mystery has come a long way since the early theories, discoveries today are still necessary pieces of the bigger picture.

You have to like puzzles a discovery.

It's certainly important, but it will not answer all your questions.

It will be a big and important piece in your puzzle.

Mass extinction events are incredibly powerful tools for us to understand the way life and ecosystems operate.

And so the chicks love event is the most recent of these mass extinction events on Earth Sciences Never done right.

We just find mawr questions that need answering.

Mm hmm.