Elephant birds are members of the extinct ratite family Aepyornithidae, made up of flightless birds that once lived on the island of Madagascar. They are thought to have become extinct around 1000-1200 CE, probably as a result of human activity. Elephant birds comprised the genera Mullerornis, Vorombe and Aepyornis. While they were in close geographical proximity to the ostrich, their closest living relatives are kiwi (found only in New Zealand), suggesting that ratites did not diversify by vicariance during the breakup of Gondwana but instead evolved from ancestors that dispersed more recently by flying.

In September 2018, scientists determined that Vorombe titan reached weights of 730 kg (1,600 lb) and stood 3 m (9.8 ft) tall, making it the world's largest and heaviest bird, slightly larger than the much older Dromornis stirtoni. Other members of the family were also very large, exhibiting the phenomenon of island gigantism.

https://en.wikipedia.org/wiki/Elephant_bird