A bird of prey that flew over South Australia's Flinders Ranges 60,000 years ago was Australia's biggest eagle, researchers have confirmed.
Dynatoaetus gaffae had a wingspan of three metres and 30-centimetre talons powerful enough to grab a small kangaroo.
The first remains of the predator, which was about twice the size of a wedge-tailed eagle, were unearthed in 1956, according to Flinders University palaeontologist Ellen Mather.
More fossils were discovered in Mairs Cave and the Naracoorte Caves in 1969, which led Dr Mather and other researchers to revisit the caves two years ago.
"It wasn't until 2021 that we had all the bones of the skeleton to be able to figure out what it was," Dr Mather said.
"The Dynatoaetus is comparable to the Philippines eagle and the Harpy eagle from South America.
"It's also related to the Old World vultures and it doesn't have any living descendent in Australia today."
Dr Mather and her team's findings were published in the Journal of Ornithology this week.
Scourge of the skies
Dr Mather said the fossils in the Flinders Rangers told researchers a lot about how the bird lived.
"We were able to see how it had quite large and robust leg bones, which indicate that it was a predator specialising in larger prey," she said.
"It had strong legs to be able to grab onto and take down a struggling animal.
"It could definitely grab onto a kangaroo and sink its claws in until it stopped struggling."
Associate professor Trevor Worthy said the raptor was almost as big as Haast's eagle, which was the largest ever discovered.
He said Dynatoaetus would have been a scourge to the ground-dwelling animals in its sights.
"It had giant talons, spreading up to 30cm, which easily would have been able to dispatch a juvenile giant kangaroo, large flightless bird or other species of lost megafauna from that era," Dr Worthy said.
"It was humungous."
Dr Mather said the eagle probably died out along with its prey.
"We think this eagle became extinct because its preferred prey went extinct and therefore it was unsuccessful to live off the other surviving species," she said.
The Flinders University team hopes to discover more fossils and learn more about the mighty predator.
"Then we can try and figure out it might have lived and how it interacted with its environment," Dr Mather said.
