Sixty-six million years ago, an asteroid wiped out thedinosaurs in a fiery global catastrophe. But we know littleabout how their successors, the mammals, recovered and tookover the world. Now, hidden inside ordinary-looking rocks, anastonishing trove of fossils reveals a dramatic new picture ofhow rat-sized creatures ballooned in size and began to evolveinto the vast array of species—from cheetahs to bats towhales to humans—that rule our planet today.
