The Madagascar elephant bird, the largest bird of all time
The Elephant Bird measured 3 to 3.5 m high and weighed 350 to 450 kg (up to 500 kg for the largest males). Despite its remarkable size, the Elephant Bird was not the largest bird. It was dwarfed by the New Zealand giant moa, a better-known cousin species from the different Dinornithiformes family, which could reach 4 meters. Aepyornis, however, remains the heaviest bird ever to exist, with the Moa having been shown to be lighter. This bird was incapable of flight, since it had almost no wings, even at the skeletal level. it was a runner bird like the other species of giant land birds in its family. He can achieve record accelerations to escape his predators. Disappearing more around the year 1000 than in the 17th or 18th century1,2, the æpyornis rubbed shoulders with the first men arriving in Madagascar. Even today, Malagasy people can find intact eggs which they use as urns. In some cases, these eggs have a circumference of more than 1 meter, a length of up to 34 centimeters, and a volume of 9 liters, more than seven times the volume of an ostrich egg.
Screen via : https://www.futura-sciences.com/planete/actualites/zoologie-oiseau-elephant-madagascar-plus-gros-oiseau-tous-temps-73021/