There were about 25 species in the Phorusrhacidae family of flightless birds. All of them are now extinct. They once lived in South America, and a few species later spread into Central and North America.

Terror birds had huge heads, strong hooked bills, tiny wings, and long, powerful legs with sharp, clawed toes.

Terror birds became extinct at least 1 million years ago. Depending on the species, they stood about 3 to 9 feet (0.9 to 2.7 m) tall. The largest species weighed up to about 770 pounds (350 kg).

Terror birds were meat-eating predators. They used their powerful hooked bills to strike, injure, and kill prey, then tore the meat into pieces before swallowing it.