Phorusrhacidae

Phorusrhacidae, commonly known as terror birds, were a family of extinct predatory flightless birds that lived in the Americas from the Paleocene to the Pleistocene epochs. They are characterized by their large size, powerful legs, and formidable beaks, which were likely used to hunt and kill prey. The exact phylogenetic placement of Phorusrhacidae within the avian tree of life has been a subject of debate, but current consensus places them within the order Cariamiformes, alongside the extant seriemas.

The fossil record of Phorusrhacidae is most extensive in South America, where they were apex predators for millions of years. Different genera within the family varied in size, with some reaching up to 3 meters (10 feet) in height. Their diet likely consisted of mammals, reptiles, and other birds. While the exact mechanics of their hunting strategies are unknown, their robust build and sharp beaks suggest an active predatory lifestyle.

Phorusrhacids went extinct gradually, with their decline coinciding with the arrival of placental mammals, including large predators like the saber-toothed cats, and potentially environmental changes. Some species may have survived into the Pleistocene. The discovery of phorusrhacid fossils has provided significant insights into the prehistoric ecosystems of the Americas and the evolutionary history of birds.