Photo from Thunderbird site listApparently Argentavis magnificens is the largest flying bird ever discovered. Dr. Kenneth E. Campbell, (one of the discoverers) in front of the 25 ft. wingspan Argentavis Magnificens. Display seen at the Natural History Museum, Los Angeles.
Currently accepted estimates:
* Wingspan: 5.7 to 8.3 m (19 - 28 ft)
* Length: 3.5 m (11.5 ft)
* Height: 1.8 to 2 m (5.9 ft - 6.5 ft)
* Weight: 65-100 kg (143 lb - 220 lb)
Source: Angelfire, Wikipedia