April 17, 2026

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The dinosaurs at your window: How birds survived the asteroid that killed all other dinosaurs

How a few unique traits helped modern-style birds—the last living dinosaurs—survive the asteroid apocalypse that took out T. rex and other mighty beasts

By Kendra Pierre-Louis, Sushmita Pathak, Alex Sugiura & Naeem Amarsy

Gary Chalker/GettyImages

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Kendra Pierre-Louis: For Scientific American’s Science Quickly, I’m Kendra Pierre-Louis, in for Rachel Feltman.

From television shows like Land of the Lost and Terra Nova to the blockbuster Jurassic Park movie franchise, Hollywood loves to envision what it would mean for humans to live alongside dinosaurs.

But the truth is we already do. Birds, after all, are dinosaurs. But how did birds survive the extinction event that killed so many non-avian dinosaurs?

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Steve Brusatte, a professor of paleontology and evolution at the University of Edinburgh and the author of the upcoming book The Story of Birds, dug into the subject of bird survival in the May issue of Scientific American. He’s here today to speak with us about it.

Thanks so much for joining us today, Steve.

Steve Brusatte: My pleasure, Kendra. Thank you.

Pierre-Louis: So it’s funny because I think most people by now know that birds are dinosaurs, but I don’t think most of us really kind of think about how they survived while, like, dinosaur species like the T. rex didn’t. You recently wrote a feature for Scientific American digging into how birds survived. What interested you in the subject?

Brusatte: Yeah, so the article I wrote for Scientific American, it tackles that question, which really has been a mystery for a long time among paleontologists: Why is it that birds were the only dinosaurs to survive that asteroid that fell out of the sky 66 million years ago and changed the trajectory of evolution?

And this is also something I write about in The Story of Birds; it’s in one of the middle chapters. So the book tells the whole story of birds: how they evolve from dinosaurs, what it means that birds are dinosaurs, how birds survive the asteroid and then all the amazing things birds have done since then. But of that entire story, I really do think it is this mystery of “Why did birds have what it took to get through that asteroid, to stare down that asteroid, to endure that worst day in the, the history of life?”

And part of the mystery here is it just seems so unfathomable. You have these dinosaurs like T. rex and Triceratops and the long-necked dinosaurs. They had been around for over 150 million years. They lived all over the world. They were at the top of the food chain. They were the biggest meat eaters, the biggest plant eaters. They had incredible diversity. They were utterly dominant. And then all of a sudden they’re gone. But one peculiar type makes it through, and those are the birds.

It’s an incredible mystery, and it really has been a mystery for scientists until quite recently, and I do think—not that we understand it completely now. We’re dealing with fossils. We’re dealing with these clues from millions of years ago that we have to interpret like detectives. But I think we have a pretty good handle now on why birds survived.

Pierre-Louis: Okay, so before we get there, can you, like, set the scene of what it was like back when birds and dinosaurs co-existed? I mean, I know birds are dinosaurs, but, like, when birds and, like, kind of the charismatic dinosaurs that we all think of, when they overlapped, what was it like?

Brusatte: Two hundred and thirty million years ago or so, back in the Triassic period, that’s when the first dinosaurs entered the scene. And this was back during the supercontinent of Pangaea, when all of the world was globbed together into this one giant landmass. And it was on that supercontinent that the first mammals and the first dinosaurs had their origin story.

Now, the first dinosaurs were quite simple. They were small. They were the size of dogs, the size of people ...

Pierre-Louis: Hold on—so you’re telling me that the early dinosaurs were the size of dogs? I could have had a pet dinosaur?

Brusatte: [Laughs.]

Pierre-Louis: [Laughs.]

Brusatte: You could’ve. You could’ve. The first dinosaurs, they would’ve been really cute. They would’ve been quite adorable. You could’ve held ’em in your arms. They looked nothing like a T. rex, nothing like a Brontosaurus, nothing like a Triceratops. Those dinosaurs would come later.

And really, th