The end of the dinosaurs: What ended the age of the dinosaurs?

Why this question matters

The extinction of the non-bird dinosaurs about 66 million years ago is one of the most studied events in Earth's history. Two suspects overlap in time: an asteroid impact and huge volcanic eruptions in India. The case is about how scientists weigh competing explanations, and how sure they can be.

The evidence

The exhibits in this case. Their full details open in the app.

• Scientific findingReported in 1980

  The iridium layer

• Scientific findingIdentified as the impact site in 1991

  The Chicxulub crater

• Scientific findingIn the boundary layer

  Shocked quartz and glass beads

• Scientific findingAround 66 million years ago

  The Deccan Traps

How the investigation works

After the briefing and exhibits, you complete three steps. Every answer is explained, and the verdict lists the sources.

1. 1

   Chronology

   Put the events back in order, oldest first. BC and AD are handled correctly, and there is no year zero.

2. 2

   Cause and consequence

   Match each clue to the event that best explains it, and only where the evidence supports the link.

3. 3

   Supported conclusions

   Sort claims into supported, going beyond the evidence, or contradicted. Every answer explains why.

Sources

• Alvarez et al. 1980, Science
• Schulte et al. 2010, Science (review)

Case content last checked 2026-10-13. Not reviewed by an independent historian. Found an error? Tell us.