For a long time, the prevailing theory was that dinosaurs were already in decline before the Chicxulub asteroid struck Earth ...

Human activity may be triggering the greatest extinction event since the asteroid impact that wiped out the dinosaurs, according to scientists. Their study, based on a review of decades of research on ...

Silhouette of the Tyrannosaurus called Stan. This "tyrant lizard king," was excavated and prepared by the Black Hills Institute. © Louie Psihoyos/CORBIS What ...