Gerta Keller, Princeton University (IMAGE) Princeton University Caption Princeton geoscientist Gerta Keller and a research team have compiled new evidence disproving a popular theory that an asteroid wiped out the dinosaurs about 65 million years ago. Examinations at several new sites have produced biotic evidence -- the fossilized traces of plants and animals -- indicating that a massive die-off did not occur directly after a proposed asteroid strike but much later. Credit Denise Applewhite Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.