Some dinosaurs may have been in trouble even without the asteroid

Sixty-five million years ago, an asteroid six miles in diameter cannoned into Earth. The collision triggered the catastrophic downfall of a vast and thriving dinosaurian ecosystem, ultimately ending with their extinction. Only that's not what happened. Not at all exactly. (Cue Sam Neill's voice.) » 5/02/12 9:55am 5/02/12 9:55am