Largest flightless bird weighed 600 KILOS with giant two-foot head and roamed Australia 50,000 years ago

THE world’s biggest-ever bird weighed as much as a cow and had a head as long as your forearm, according to research.

The flightless avian Dromornis stirtoni roamed the plains of Australia 50,000 years ago, plodding along on two hind legs like an emu.

It was the largest member of an extinct group of creatures called the “mihirungs” – an Aboriginal word for “giant bird”.

Writing in the journal Diversity this week, scientists described how they analysed the ancient skulls of mihirungs to get a better idea of their brains.

They discovered that the animals’ enormous noggins left little room for their grey matter, giving rise to some oddly shaped skulls.

“Together with their large, forward-facing eyes and very large bills, the shape of their brains and nerves suggested these birds likely had well-developed depth perception and fed on a diet of soft leaves and fruit,” said study lead author and Flinders University researcher Dr Warren Handley.

Brian choo

Giant flightless birds roamed the plains of Australia until about 50,000 years ago[/caption]

“The shape of their brains and nerves have told us a lot about their sensory capabilities, and something about their possible lifestyle which enabled these remarkable birds to live in the forests around river channels and lakes across Australia for an extremely long time.”

Nicknamed “Thunder Birds”, the mihirungs lived across Australia for many millions of years.

The largest species – Dromornis stirtoni – could grow up to 10ft (3m) tall and weigh about 600kg (1,320lb).

The research team studied four fossilised skulls from four species of mihirungs found across Australia.

Peter Trusler

Dromornis stirtoni had a head as long as your forearm[/caption]

The specimens included a 7million-year-old Dromornis stirtoni cranium, as well as a 24-million-year-old Dromornis murrayi and 12-million-year-old Dromornis planei and Ilbandornis woodburnei skulls.

The researchers discovered that mihirung brains and nerves were most like those of modern day chickens and Australian mallee fowl.

“The unlikely truth is these birds were related to fowl – chickens and ducks – but their closest cousin and much of their biology still remains a mystery,” said study author Dr Trevor Worthy.

“While the brains of dromornithids were very different to any bird living today, it also appears they shared a similar reliance on good vision for survival with living ratities such as ostrich and emu.”

The team used CT scans of the skulls to create casts of the creatures’ brains.

The largest and last species Dromornis stirtoni, which died out 50,000 years ago, was an “extreme evolutionary experiment”, Dr Worthy said.

“This bird had the largest skull but behind the massive bill was a weird cranium,” he explained.

“To accommodate the muscles to wield this massive bill, the cranium had become taller and wider than it was long, and so the brain within was squeezed and flattened to fit.”

That bizarre cranium measured up to two feet long and supported a powerful, big beak.

Dr Worthy believes the unusual shape was the resut of runaway evolution.

“It would appear these giant birds were probably what evolution produced when it gave chickens free reign in Australian environmental conditions,” he said.

“They became very different to their relatives the megapodes – or chicken-like landfowls which still exist in the Australasian region.”

It’s not the only giant avian to have walked the planet.

Monster penguins that stood as tall as a human roamed the United States 40million years ago, according to research.

A huge species of bird three times bigger than an ostrich roamed Europe with our early ancestors 1.5million years ago.

What do you make of the giant bird? Let us know in the comments!

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