Argentavis was the largest bird ever to fly. Argentavis belonged to a group of giant birds called Teratorns. The most famous member of this family was Teratornis. Teratorns may be the inspiration for the Thunderbird legends. Of course, Argentavis and the other 2 Teratorns couldn't shoot lightning from their eyes and create thunder very time they flapped their wings. But there have been sightings of Teratorns from Illinois to Texas to Alaska. In July 25, 1977, 3 boys were playing in a backyard, when 2 very large birds, possibly a male and a female, attacked. 2 of the boys escaped, but one didn't. The possible female grabbed his shirt and carried him 2 feet into the air before deceiding "This isn't worth it." She then dropped the struggling boy and flew away with her mate. Another sighting had a pilot flying in Alaska when he saw a massive bird the size of his plane. The Illinois sighting desrciption matched an Andean Condor, but the size description was bigger than any Andean Condor, which is the largest flying bird today.