Terror Birds

Phorusrhacids, an extraordinary group of animals, took the throne as top predators in South America after the dinosaurs died out. “Titanis walleri,” one of the largest species, evolved in South America and spread North after the Isthmus of Panama land-bridge formed. Their wings developed into meat hook-like structures that, when outstretched, could perform a hacking motion. Even more terrifying, many of these Cenozoic Era beasts were fast runners.