what killed the dinosaurs

New research has revealed that many dinosaur populations were declining long before the last extinction event.  
Schoolchildren have been taught for generations that the dinosaurs were likely wiped out by an asteroid strike that hit present-day Mexico around 66 million years ago. The vision presented in schools is one of a thriving dinosaur population entirely wiped out almost overnight, as the asteroid barreled through the atmosphere […]

Dinosaur Populations Were Declining Before Asteroid Hit, Study Finds