The largest living bird, a member of the Struthioniformes, is the ostrich (Struthio camelus) reaching a height of over 2.7 m (9 ft) and weighing over 156 kg (345 lb). Eggs laid by the Ostrich can weigh 1.4 kg (3 lb) and are the largest eggs in the world today.
The largest bird in the fossil record may be the extinct elephant birds of Madagascar, which were related to the ostrich. They exceeded 3 m (10 ft) and 500 kg (1,120 lb). The last of the elephant birds became extinct about 300 years ago. Of almost exactly the same proportions as the largest elephant birds was Dromornis stirtoni of Australia, part of a 26,000-year old group called mihirungs of the family Dromornithidae. The tallest bird ever however was the Giant Moa (Dinornis maximus), part of the moa family of New Zealand that went extinct about 200 years ago. This moa stood up to 3.7 m (12 ft) tall when it was erected in an unnatural position, but weighed about half as much as a large elephant bird or mihirung due to its comparatively slender frame. The largest carnivorous bird was Brontornis, an extinct flightless bird from South America which reached a weight of 350 to 400 kg (770 to 880 lb) and a height of about 2.8 m (9 ft 2 in).