Paleontologists Discover New Mammal Fossils Hidden in Rocks
Clip: Season 46 Episode 17 | 5m 44s | Video has closed captioning.
Hidden inside ordinary-looking rocks, an astonishing trove of fossils paints a dramatic picture of how rat-sized creatures ballooned in size and began to evolve into the vast array of species—from cheetahs to bats to whales to humans—that rule our planet today.
Problems Playing Video? | Closed Captioning