The largest birds that ever lived are the elephant birds of Madagascar, which became extinct around 1,000 years ago. The largest species among these was Vorombe titan (“big bird” in Malagasy), which stood as tall as 3 metres (9 feet 10 inches). It is estimated to have weighed as much as 860 kilograms (1,895 pounds 15 ounces) – with an average weight of 642.9 kilograms (1,417 pounds 5 ounces) – as confirmed in a paper published in Royal Society Open Science on 26 September 2018.In the 19th century, the largest bird species was considered to be Aepyornis maximus – another type of elephant bird – while in more recent years, the largest birds were thought to be Dromornis stirtoni with the upper limit of body mass of these birds recorded to be 728 kilograms (1,604 pounds), with an average weight of 584 kilograms (1,287 pounds). However an extensive study of various elephant bird bones and computer modelling carried out in 2018 determined that the largest of these birds belonged to a different species: Vorombe titan.The new research was conducted by James Hansford and Samuel Turvey – both of the Institute of Zoology at the Zoological Society of London, UK.Only the Moas from New Zealand may have been taller than the elephant bird (reaching just over 3 metres), but they were not so massively built. The elephant bird's eggs were larger than those of any dinosaur, and are the largest single animal cell ever to exist on Earth. They had a liquid capacity of 2 gallons – the equivalent volume of 150–180 chicken eggs.