When the big asteroid hit Mexico 66 million years ago, it set off wildfires, tsunamis and massive clouds of dust that darkened the skies, killed much of Earth’s plant life and triggered a chain of ecological catastrophes that led to the rapid extinction of most of the dinosaurs.

But some life survived, including mammals that may have taken refuge in burrows and scavenged. There were also many small, feathered, hollow-boned dinosaur species that somehow survived. Their descendants are still with us today — around 10,000 species of small, feathered, hollow-boned animals that we call birds.

The category of “reptiles” contains birds. Lizards, snakes, crocodiles and turtles are commonly classified as reptiles because they all share a common ancestor, some scaly, cold-blooded creature that evo

See Full Page