Influence of Earth’s history on the dawn of modern birds

The evolution of modern birds was greatly shaped by the history of our planet’s geography and climate. New research finds that birds arose in what is now South America around 90 million years ago, and radiated extensively around the time of the Cretaceous-Paleogene extinction. The new research suggests that birds in South America survived this event and then moved around the world via multiple land bridges while diversifying during periods of global cooling.
Paleontology News — ScienceDaily