The mostly flightless, meat-eating dinosaur descendents were the size of dogs at their smallest, but the largest known examples reached nearly 10 feet in height. Now, however, paleontologists have confirmed that a possibly unknown species of terror bird grew up to 20 percent bigger than any previously known,

Evolutionary biologist Federico Degrange from Argentina's Center for Research in Earth Sciences and colleagues found the bird's shinbone was marred with teeth marks of an ancient crocodile relative, Purussaurus, thought to grow up to 9 meters (30 feet) long.

A Colombian rancher has discovered a fossilized bone that points to the existence of a giant terror bird species. The fossil, an enormous leg bone found in the Tatacoa Desert, suggests that this bird stood over three meters tall,