Imagine a 230kg, two-metre tall goose.
It sounds like the stuff of nightmares. Or a poultry chef's dream.
Australian scientists believe that is close to what a mega bird that roamed the country in prehistoric times looked like.
Researchers have been able to provide the first glimpse of the "giga-goose" - Genyornis newtoni - thanks to the discovery of a megafauna skull in remote South Australia.
"It was like an emu, probably the same height but about five or six times heavier. It was a much bulkier bird," study co-author Trevor Worthy of Flinders University told AAP.
An intact fossil of the mammoth bird's skull was discovered in the remote dry South Australian salt bed of Lake Callabonna several years ago, changing the way researchers perceived it.
Previously, only a damaged skull had been found in 1913, but did not provide enough bone to re-imagine the "ancient thunderbird".
"With this new skull we have started to piece together the puzzle which shows, simply put, this species to be a giant goose," lead author Phoebe McInerney said.
The massive bird would not have run very fast, but lived along rivers or lakes while eating soft plants and fruit with its strong beak.
"It would have needed a lot being a big bird. It would have had to gobble up a lot of soft plants," Dr Worthy said.
It had unusual adaptations for the aquatic habitat like being able to protect its ears and throat from ingesting water while submerged.
However, these adaptations may have led to its extinction about 45,000 years ago as freshwater bodies in northern South Australia are now primarily salt lakes.
Waterfowl species such as the Australian magpie goose or the South American screamers likely diverged from the original big bird.
The discovery was a surprise for researchers as most of the family line acquired a different shaped beak.
"Relatives have a different shaped head with a high beak, but this one is much lower and rounder and more like your standard goose except the head is 250mm long," Dr Worthy said.
"It is totally unique ... it is the last of a family that went extinct in Australia."
Researchers are planning to head back to the salt plains to see what else strong winds have uncovered to help form a more complete picture of the bird.
"You never know what the weather has exposed because it's the wind and occasional flood that expose the fossils - it's just serendipity to what you actually might find," Dr Worthy said.
The research was published in the Historical Biology journal.
