Watch CBS News

What happened to the dinosaurs?

Name: What happened to the dinosaurs?
Uploaded: 2014-06-08T18:26:00-0400
Duration: 1 min 5 s
Description: One theory is that a huge comet or asteroid violently changed the environment. Mark Norell, head of Paleontology at the American Museum of Natural History, says there are other theories too.

One theory is that a huge comet or asteroid violently changed the environment. Mark Norell, head of Paleontology at the American Museum of Natural History, says there are other theories too.