Bad timing can be deadly. The asteroid that wiped out the dinosaurs smashed into Earth during a period of environmental turmoil when the ancient food web was vulnerable to collapse, states a new analysis in the journal Biological Reviews.
By piecing a detailed timeline together, researchers were able to show there were some significant shifts happening -- essentially weakening the food web -- in the few million years before the Chicxulub came calling. The environmental upheaval at the time could not have killed the dinosaurs on its own -- but it made them much easier to kill off. A few million years earlier, when the food web was stronger, or later, when new species could have evolved, some of them might have survived the asteroid.
-- Los Angeles Times