Plankton (IMAGE) Princeton University Caption Princeton University researchers found that massive, prolonged eruptions of the Deccan Traps in India gradually eliminated species and resulted in the Cretaceous-Tertiary mass extinction that killed the dinosaurs 65 million years ago. Marine sediment trapped between Deccan lava flows revealed that a species known as planktonic foraminifera -- widely used to gauge the severity of prehistoric disasters -- succumbed to lava mega-flows and volcano-induced environmental stress such as acid rain and drastic climate changes. As conditions on Earth worsened, large, variedspecies (left) were eliminated. The no more than seven or eight smaller species (right) that remained dwarfed further. Credit Courtesy of Gerta Keller 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.