Vorombe titan's name means big bird in Malagasy and Greek - but it bore little resemblance to the canary yellow character from children's TV show Sesame Street.

Standing almost three metres tall, the ostrich-like elephant bird weighed just under a tonne (800kg).

Experts have spent decades poring over conflicting evidence and arguing about what was the largest bird that ever lived.

Now a new study of Madagascar's elephant birds has ended the debate and handed the crown to V. titan, according to researchers from the Zoological Society of London (ZSL).

Previously, a specimen of the bird described in 1894 was thought to be an unusually large example of a smaller species, Aepyornis maximus.

The new study found that V. titan was a distinct species, and in fact different enough from other elephant birds to justify placing in its own genus, or animal family. Vorombe is its genus name.

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

V. titan is the 16th recognised species of elephant bird, now known to occupy three genera.

Elephant birds became extinct around 1000 years ago after a long period co-existing with early human inhabitants of Madagascar.

Despite their powerful legs and fearsome talons they were peaceful vegetarians, living mainly on fruit. One theory is that they were hunted to extinction by humans.

The research appears in the Royal Society journal Open Science.

Australian Associated Press