Vultures are found everywhere in the world, except for Australia and Antarctica.
But this hasn’t always been the case.
The remains of an extinct species have been found down under — and a depiction of what it might have looked like has been unveiled at the Naracoorte Caves, by Flinders University palaeontologist Ellen Mather.
Dr Mather and other researchers have spent several years studying the vulture and other extinct giant birds from Australia’s past.
Crucial to their understanding was the examination of bones of the vulture, Crytopgyps lacertosus, gathered from the submerged Green Waterhole at Tantanoola in South Australia’s south east.
Wings, shoulder and spine
The find was made in 1978 and the bones have been kept in storage.
Dr Mather said the fossils were particularly special, as they were mostly from one individual bird and included parts of the skeleton not examined before.
The fossils include most of the bones from the wings, as well as bones from the shoulder and spine.
“When these birds were alive there was a pool of water at the bottom of the site in Green Waterhole cave,” Dr Mather said.
“Today it is almost completely submerged so you have to go diving to get the fossils, but back then it would have been mostly dry.
“The living bird would have possibly drowned in the pool and its bones sunk to the bottom.”
The fossils were buried in calcite rafts at the bottom of the cave, which have been tested using uranium-series dating by John Hellstrom from University of Melbourne.
Dr Hellstrom’s tests indicated the fossilised vulture was alive about 60,000 years ago, and that the species had survived up until the time of the mass extinction of Australia’s megafauna 10,000 years later.
Extinct eagle also identified
Dr Mather said the fossils also suggested the vulture was more primitive than previously thought, and lacked an adaption common in most modern vultures that gave them extremely light wing bones filled with air cavities.
The picture to be unveiled at the Naracoorte Caves also depicts Dynatoaetus pachyosteus, a newly identified extinct eagle.
Fossils of this species have only been found at Naracoote so far.
Dr Mather said it appeared the eagle — although a similar size to the modern wedge-tailed eagle — was more closely related to the large-crested serpent eagle and Philippine eagle, found today in jungle environments.
“Based on where they’re found, these fossils would be within a few 100,000 years old,” Dr Mather said.
“So quite recent, geologically speaking.”
Dr Mather said eagle fossils were rare and it was difficult to know when the eagle and its larger relative, Dynatoaetus gaffae, which has been found at Naracoorte and in the Flinders Ranges, became extinct.
But she said examination of the newly identified species showed it was likely to have been more powerful and heavily built than a present-day wedge-tailed eagle.
Why the wedge-tailed eagle survived
Dr Mather said fossil materials indicated that when the extinction of megafauna and Australia’s ancient vultures took place about 50,000 years ago in the Pleistocene era, it was generally smaller birds that were more able to survive than larger ones.
“The wedge-tailed eagle was probably quite lucky because it was what we call a generalist; it wasn’t too fussy about how it hunted or what it hunted or where it lived,” she said.
“[It] can practically be found over all the continent today and that probably contributed to its success where others failed.”
She said as a specialist in carrion, the vulture would have been very reliant on having large-bodied animals around to provide carcasses for it to feed on.
“If those large-bodied animals die out, then you’re in a bit of trouble,” she said.
Dr Mather said the question of why the megafauna had died out was still being thoroughly debated.
“There’s two camps arguing how much of that is as a result of climate change and the other as a result of human arrival and hunting,” she said.
“It’s quite likely there was a bit of interplay between the two — perhaps some species might have survived longer but it’s still a matter of debate.”
The artwork by John Barrie, a South Australian artist and natural historian, was unveiled on November 16 and will remain on display at Naracoorte Caves.