Topics Animals, plants and life

How did dinosaurs go extinct?

Most dinosaurs died out about 66 million years ago, after a huge asteroid struck what is now Mexico's Yucatán Peninsula. The impact left the Chicxulub crater, and a thin layer of rock around the world, rich in the metal iridium, marks that moment. Most scientists agree the impact was the main cause of a mass extinction that wiped out roughly three quarters of plant and animal species.

What makes it interesting is how much is still argued. Huge volcanic eruptions in India, called the Deccan Traps, were also pumping gas into the air around the same time, and researchers debate how much they added. And the story has a twist: dinosaurs did not entirely vanish. Birds are living dinosaurs, descended from small feathered ones that made it through.

An episode would walk through the evidence step by step, from the iridium layer to the crater, then look at what the impact likely did to the sky, the oceans and the food chain. It would also say plainly where scientists disagree. bre's hosts are AI and can be wrong, so treat it as a curious starting point, then press Talk to ask your own questions.

What a bre episode would cover

An outline of the episode bre would make for this question. Every episode is written fresh when you ask, so yours will differ.

  1. The world before the impactWhat life looked like at the end of the Cretaceous, and why dinosaurs were thriving rather than fading away.
  2. The clue in the clayHow a thin layer of iridium-rich rock found around the globe pointed scientists toward an asteroid.
  3. Finding the Chicxulub craterHow a buried crater in Mexico matched the date and the size needed to fit the story.
  4. What the impact did nextThe likely chain of events: blast, fires, dust blocking sunlight, and a collapse of plants and the animals that ate them.
  5. The volcano questionThe Deccan Traps eruptions, and why scientists still debate how big a role they played.
  6. Who survived, and whySmall animals, burrowers, swimmers and some birds made it through, and the reasons are partly educated guesses.
  7. Dinosaurs are still hereHow modern birds descend from dinosaurs, and what that changes about the word extinct.

How the episode might open

A sample exchange between two of bre’s AI hosts, bre and Tess. Both are AI; this is written by AI, as every bre episode is.

  1. breAI host

    Okay, let's start with the picture. A rock roughly the size of a city lands in what is now Mexico. Most people stop the story there. But the rock is only the first minute of something that lasted years.

  2. TessAI host

    Right, and my question is the practical one. If you were a dinosaur that day, what actually got you? The blast, or what came after?

  3. breAI host

    For most of them, probably what came after. Close to the crater, the blast and fires were brutal. Farther away, the bigger problem was likely a darkened sky and a food chain that stopped working.

  4. TessAI host

    So it's less a single hit and more everything going hungry.

  5. breAI host

    That's the leading idea, yes. Though I should say, scientists still argue about the details, and volcanoes in India were also erupting around then.

  6. TessAI host

    Wait, so there might be two culprits? Okay, but real talk, how sure are we about the asteroid part?

  7. breAI host

    Pretty sure it happened and pretty sure it mattered a lot. The crater exists, and the dating lines up. What's debated is how much the volcanoes helped or hurt.

  8. TessAI host

    Good. I like a mystery with edges on it. Where do we start?

Questions people also ask

Did an asteroid really kill the dinosaurs?
Most scientists think an asteroid impact about 66 million years ago was the main cause of the extinction of non-bird dinosaurs. Evidence includes the Chicxulub crater and a global iridium-rich layer. Some researchers argue volcanic eruptions contributed, so the exact mix of causes is still debated.
Are any dinosaurs still alive today?
Yes, in a sense. Birds descended from small feathered dinosaurs that survived the extinction. So when people say dinosaurs went extinct, they usually mean the non-bird dinosaurs, such as Tyrannosaurus and Triceratops.
Why did some animals survive when dinosaurs did not?
No one knows for certain. Small body size, needing less food, burrowing, living in water, and being able to eat seeds or scraps may all have helped. Those are well-supported ideas, but they are still interpretations of the fossil record.
How long did the dinosaur extinction take?
The impact itself was nearly instant, and its worst effects likely unfolded over months to years. The full recovery of ecosystems took much longer, likely hundreds of thousands to millions of years. Exact timings are still being refined.

Related topics

More: all 300 topics, animals, plants and life, or the longer reads on /learn.

bre’s hosts are AI, and every episode is generated, so they can be wrong: check anything that matters. This page outlines what an episode would cover. It is for interest and learning, not medical, financial or legal advice.