Father-son scientists Luis and Walter Alvarez piece together one of the greatest mysteries of all time: What really happened to the dinosaurs? Dive into this fun and informative middle grade nonfiction book, which outlines the many important scientific discoveries that aided the Alvarezes in their search for answers. Cretaceous earth was known as the age of dinosaurs. But really, it was the age of LIFE--scaled and feathered, furry...