Dinosaur extinction.

 As you know, dinosaurs are no more. They all died. And those who lived have evolved already. And scientists have come up that an asteroid had killed (most of) them. There have been 5 mass extinctions so far. They are: 

1. (440 MYA) The Ordovician extinction. It killed 60% of the world's species. (The least killed mass extinction)

2. (358 MYA) The Devonian extinction. It killed 75% of the world's species.

3. (250 MYA) The Permian extinction. It killed 96% of the world's species. (The most killed mass extinction, also it was terrible after the extinction)

4. (200 MYA)The Triassic extinction. It killed 70% of the world's species. 

5. (66 MYA) The Cretaceous extinction. It killed 75% of the world's species.

Those are the are 5 mass extinctions. And let me tell you that the pet you have right now, yes, right now, was a dinosaur! And then evolution made them look less frightening and stuff. So you may have a pet. And if you have one, it used to be a dinosaur. Even the birds were dinosaurs! 

So let's talk about the Permian extinction. So the Permian extinction was the absolute worst extinction out of the other 4. The formation of Pangea (a supercontinent) caused immense climate change and the change of environment. And it was terrible. (For the things that lived there) And very few species survived. 

But despite the terrible mass extinctions in history, there was this one animal that survived all the mass extinctions. And it is known as "The Tardigrade" Also known as a water bear because they mostly live in water. These things survived the 5 mass extinctions. And the amazing thing is, they might be living in your backyard right now! You can't see them but they might be there! These Tardigrades are also pretty much invincible. If you try to throw a tardigrade on space, it won't work, you can't kill it. Stop. You just cannot kill it. And yes, they are still living to this day. And they will probably survive an asteroid explosion. And also they are microscopic animals and they are also invertebrates.