Paleontologists thought that a fossil found in South Australia was a grave eagle. It's the first one discovered in the country and it's a vulture.

Between 500 and 50,000 years ago, this vulture would have been powerful and it is the fossil that shows it. It's an 'Old World' vulture, but not in Australia.

The diversity of the megafauna and other wildlife in this part of the world was highlighted by the reclassification.

Eagle and vulture comparisons. (Ellen Mather, Flinders University Paleontology Lab)

"We compared the fossil material to birds of prey from around the world, and it became clear right away that this bird was not adapted to being a hunter, and so was not a hawk or an eagle," says paleontologist Ellen Mather.

The lower leg bone isn't strong enough to support the musculature needed to kill prey. It was confirmed that the bird was a vulture when we put it in an evolutionary tree.

A fragment of a wing bone was found near the Kalamurina homestead in 1901, the beginning of the story. It was described as a descendant of the wedge-tailed eagle within a few years.

Researchers began to question the classification of the fossil in recent years. It was suggested that there may have been Old World vultures in Australia during the time of the last ice age.

The researchers were able to prove it after discovering fossils from the Wellington Caves in New South Wales.

The Diprotodon and the marsupial lion are two large beasts that are now extinct.

The mystery of what happened to so many megafaunal carcasses was solved by the discovery.

They were here now. They have been hidden from view.

The diversity of predatory birds in Australia was much greater in the past than it is now.

There are no vultures left in Australia, and they play a crucial role in speeding up carcass decay.

The researchers think that the demise of the vultures would change the status quo, as other scavengers started to fill the same role.

Many of the birds would feed on one carcass if C. lacertosus acted like its modern-day relatives. This would have made it a better animal.

"We're familiar with a wedge-tailed eagle picking at a dead animal on the side of the road." A very different bird would have filled the role of carrion consumer a long time ago.

The research was published in a journal.