Forgive me for my hideous pun. Now, imagine a land of giant, flightless, predatory birds. Paradise, right? If you’re a bird. If you’re a mammal, you may be stalked, run down, and killed by a sharp beak to the skull. This is how life was like in North and South America 5-2 million years ago. The Phorusrhacids, commonly known as “terror birds,” were apex predators. Their ancestors evolved in South America and migrated north – the only giant predator to do so during the Great American Interchange (when North and South America were joined via what is now Panama). This jolly group of birds stood between 3-10 feet tall and could run an estimated 30mph. Isn’t that nice? I think so. Another fun factoid: the Kelenken, a member of the Phorusrhacidae, had the largest skull of any known bird. The beak was 18in long. So the next time you see an ostrich, just be glad it isn’t a terror bird.