Teratorn
Argentavis magnificens. A partial skeleton of this enormous teratorn was found from La Pampa, Argentina. It is the largest flying bird known to have existed. It is the oldest known teratorn, dating to late Miocene, about 6 to 8 million years ago, and one of the very few teratorn finds in South America. Initial discovery included portions of the skull, incomplete humerus and several other wing bones. Even conservative estimates put its wingspan at 6 meters and up (some 20 ft), and it may have been as much as 8 metres (26 ft). The weight of the bird was estimated to have been around 80 kg (176 lb).