The analysis of hundreds of fossilized droppings (plus a little bit of petrified vomit) from roughly 230 million years ago ...

Lava flows like these provide evidence of a rash of volcanic activity for at least 500,000 years leading up to the extinction of the dinosaurs. Rare Metal The metal iridium, which is similar to ...

According to scientists who maintain that dinosaur extinction came quickly, the impact must have spelled the cataclysmic end. For months, scientists conclude, dense clouds of dust blocked the sun ...