'World's largest ever bird' named after much debate

After decades of conflicting evidence, scientists said on Wednesday they have finally put the 'world's largest bird' debate to rest, conferring the title on Vorombe titan -- an extinct Madagascan species which was three metres tall and weighed up to 800 kg.

The research, published in the journal Royal Society Open Science, also discovered unexpected diversity in these Madagascan creatures.

It was previously suggested that up to 15 different species of elephant birds had been identified under two genera. However, the latest research by the Zoological Society of London (ZSL) in the UK shows, in fact, that this is not the case.

"Elephant birds were the biggest of Madagascar's megafauna and arguably one of the most important in the islands evolutionary history -- even more so than lemurs," said James Hansford from ZSL's Institute of Zoology.

"This is because large-bodied animals have an enormous impact on the wider ecosystem they live in via controlling vegetation through eating plants, spreading biomass and dispersing seeds through defecation. Madagascar is still suffering the effects of the extinction of these birds today," Hansford said.

Researchers analysed hundreds of elephant bird bones from museums across the globe to uncover the world's largest bird, while also revealing their taxonomy is in fact spread across three genera and at least four distinct species.

The research, constitutes the first taxonomic reassessment of the family in over 80 years, researchers said.

Elephant birds (belonging to the family Aepyornithidae) are an extinct group of colossal flightless birds that roamed Madagascar during the Late Quaternary, with two genera (Aepyornis and Mullerornis) previously recognised by scientists.

The first species to be described, Aepyornis maximus, has often been considered to be the world's largest bird, researchers said.

In 1894, British scientist CW Andrews described an even larger species, Aepyornis titan, this has usually been dismissed as an unusually large specimen of A maximus.

However, ZSL's research reveals Andrew's 'titan' bird was indeed a distinct species.

The shape and size of its bones are so different from all other elephant birds that it has now been given the new genus name Vorombe by ZSL.

"Without an accurate understanding of past species diversity, we can't properly understand evolution or ecology in unique island systems such as Madagascar or reconstruct exactly what's been lost since human arrival on these islands," said Professor Samuel Turvey from ZSL's Institute of Zoology.

"Knowing the history of biodiversity loss is essential to determine how to conserve today's threatened species," Turvey said.