♪.

Clues, clues, lookin’ for clues…. Oh!

It’s you! Hi! You were probably expecting Jessi, right?

Well, she and Squeaks will be back next time, but right now they're off doing a bit of detective work in Yucatán,, Mexico! You might say they’ve flown south for the winter. And of course I approve of that!

Very bird-like of them. You see, we teamed up because we got curious about one of the greatest mysteries of all time: What happened to the dinosaurs? If you know me, you know that I loooove dinosaurs.

And a long time ago — around 65 million years! — the dinosaurs were large and in charge. They had ruled the Earth for over 160 million years. And then, something strange happened, not just to dinosaurs, but to over half the Earth's species.

That means a type of living thing, like oak trees, or cuckoo birds like me, or humans like you. All at once, about 65 million years ago, a bunch of different species just went extinct — they were completely wiped out! That’s because something big happened, causing huge changes on Earth.

Changes in the weather, changes in the oceans … changes that made it harder for dinosaurs and other living things to find food and survive. Sure sounds mysterious! Most species will go extinct sometime, but what I wanna know is: What happened?

What caused so many species – from tiny ocean creatures to big land reptiles like. T-rex and Triceratops – to all go extinct at the same time? Scientists don’t know for sure, but they have a few different guesses.

Some scientists think it happened because of a giant rock moving through space, called an asteroid, that crashed into the Earth. As it happens, that’s just what Jessi and Squeaks went to Mexico to learn more about! And Jessi’s giving us a call right now!

How’s your vacation, Jessi?

Jessi: Terrific, Dino! Squeaks and I are here at the Yucatán Peninsula in Mexico, and we’re learning so much! We learned that 65 million years ago, an asteroid blasted in from outer space and landed right here! This asteroid was enormous — it was 12 kilometers wide, so big that it would take hours just to walk from one side to the other.

And when it landed, the explosion left an even bigger crater — a big bowl-shaped dent in the Earth. It’s called the Chicxulub crater, and it’s about 150 kilometers wide. The explosion sent lots of rocks and other debris raining down on anything nearby.

And it sent billions of tons of soot into the air! Soot is the dusty stuff that’s left over when something burns up,.

Dino: That's one powerful explosion!

Jessi: It sure was! It made the whole world really hot for a few days. And it started fires, giant waves, and huge, strong winds; and it shook the Earth, in a super powerful earthquake!

Dino: Thanks for the hot tips, Jessi. Enjoy the rest of your trip! Now, some scientists think that the explosion from the asteroid sent so much soot into the air that it blocked out the Sun. For a while, it was really dark outside, even during the day!

And without sunshine, it started to get cold, which meant some of the living things that were used to warmer weather couldn’t survive. There was another problem, too: plants need sunlight to live, so a lot of the plants back then died. Without plants, the animals that ate plants didn't have enough food, and without enough plant-eaters, the animals that ate meat went hungry too.

That’s why some scientists think the asteroid was what caused the dinosaurs to go extinct! But other scientists think there may have been another cause, and that even before that asteroid crashed into the Earth, disaster was in the air for the dinosaurs. And they think the culprit was ... volcanoes!

Because right around the time that the dinosaurs went extinct, one of the biggest volcanic eruptions in history was underway, in the area of the world that’s now India. For close to a million years, eruptions sent rocks and dust and soot onto the land and into the air. Just like with the asteroid impact, all this stuff in the air would have blocked out the.

Sun, making the Earth cooler and darker. So we don’t know for sure what darkened the skies and wiped out all those species — it could have been the asteroid, or it could have been the volcanoes, or both! We have so many clues, but the true culprit is going to remain a mystery... for now.

Either way, the dinosaurs were pretty unlucky! A lot of things went very wrong for them, all at the same time. But even though life was hard, some types of plants and animals were able to find food and shelter while the Earth was changing, and they survived!

Whatever happened all those years ago, life on Earth goes on, and we’re all here, solving mysteries together! Do you have any big mysteries you’re wondering about? Ask a grownup to help you and leave a comment below, or send us an email at kids@scishow.com.

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