The ‘Prehistoric Beaver’ That Helped Mammals Inherit Earth

Sixty six million years ago the world changed in an instant. A huge asteroid, some ten kilometers in diameter, smashed into what is now Mexico. It arrived with the force of several million nuclear bombs, and unleashed a deadly cocktail of wildfires, tsunamis, earthquakes, and volcanoes. »10/05/15 3:30amYesterday 3:30am