Scientists have just solved the 50,000-year-old puzzle of why the flightless “big bird” Genyornis Newtoni disappeared for good in its Australian habitat. According to burnt eggshell remains of the prehistoric bird, humans cooked the birds’ eggs for dinner, eventually leading to the poor creatures’ extinction.

Writing in the journal Nature Communications, the team from University of Colorado Boulder collected unburnt eggshells, mostly found in sand dunes or on the giant birds’ preferred nesting sites. They used optically stimulated luminescence (OSL) dating to analyze the age of the samples, which coincided with the settlement of the earliest humans in Australia.

But what does science know about this bird species – its appearance, way of life, and the consequence of its loss?

Burnt Eggshells: Proof Of Human Influence

"We consider this the first and only secure evidence that humans were directly preying on now-extinct Australian megafauna," said study author and geological sciences professor Gifford Miller, citing their documentation at over 200 sites across the continent.

Many of the burnt eggshell remnants exhibited heat gradient differences of almost 1,000 degrees Fahrenheit, which is nearly impossible to replicate through natural wildfires.

Eggshells of emus, flightless birds that still exist today, also showed burn patterns similar to the extinct big birds and likely underwent such conditions after humans arrived in the area.

How The Genyornis Newtoni Lived

The large flightless bird can be pictured as considerably heavier and taller than the modern emu or ostrich. It boasted tiny wings, powerful legs, and a close resemblance to ducks and geese, its living kin.

Instead of webbed feet and a duckbill, however, these big birds had big hoof-like claws on the toes and a big beak for feeding on fruit, nuts, and perhaps small prey.

Genyornis thrived in dray grasslands and woodlands, with fossil bones found in one place and suggestive of their flock-like existence. Their fossils have been located on the surface of the dry Lake Callabonna and in sections of Victoria, New South Wales and South Australia.

Previous evidence has pointed that these birds co-existed with humans for at least 15,000 years, with activities such as hunting as potential contributors to the species’ extinction. Other experts, too, believe that the disappearance of Australian megafauna was partly responsible for the continent turning drier during the last Ice Age.

Learn more information about these birds, which were the last of the large flightless "thunder birds" endemic to the continent.