Centuries ago, the Demon Ducks of Doom roamed the Earth.
True to their name, they were giant flightless birds – two-meter tall, weighing 200 kg – with massive beaks.
Now imagine sharing your neighborhood with them.
Australia’s first human inhabitants co-existed with the now-extinct duck-like bird family; Genyornis newtoni, the last of the ‘Demon Ducks of Doom’.
Not everything was terrifying about them. They laid enormous eggs – the size of cantaloupe melons which was more than 20 times the weight of an average chicken egg – which could be consumed as an important protein source.
Finding the mother
Now, even though the terrestrial birds vanished from the face of the Earth, 50,000-year-old eggshell fragments were discovered 40 years ago.
Researchers couldn’t come to a consensus about the rightful mother. Some suggested Genyornis newtoni, while others believed the shells to be from Progura birds – an extinct member of a group of species called megapodes. Progura were “chicken-like birds”, with large feet and only weighing between five and seven kilograms.
“However, our analysis of protein sequences from the eggs clearly shows that the eggshells cannot come from megapodes and the Progura bird,” explained Josefin Stiller, an assistant professor at the University of Copenhagen’s Department of Biology and one of the researchers behind the new study, in a statement.
The debate came to rest. In a new study published in the journal PNAS, University of Copenhagen researchers and their international colleagues demonstrated that they can only belong to the last of a unique duck-like line of megafauna. The Demon Ducks of Doom.
“They can only be of the Genyornis. As such, we have laid to rest a very long and heated debate about the origin of these eggs,” said co-author and UCPH Professor Matthew Collins, whose area of research is evolutionary genetics.
DNA helped identify the Genyornis newtoni
This means that DNA analysis played a crucial role in attributing the eggs to the right bird.
The researchers analyzed proteins from eggshells found in sand dunes at two different locations in southern Australia – Walleroo and Woodpoint.
They then pulverized the proteins with bleach. After collecting the various small protein parts, the researchers assembled them in the right order and explored their structure by using artificial intelligence.
The protein sequences provided them with a series of ‘codes’ for genes that could be compared against the genes of over 350 living bird species.
It was clear that the eggs were not laid by a ‘chicken-like’ bird.
“We used our data from the B10K project, which currently contains genomes for all major bird lineages, to reconstruct which bird group the extinct bird likely belonged to. It became quite clear that the eggs were not laid by a megapode, and did therefore not belong to the Progura,” explained Stiller.
“We are thrilled to have conducted an interdisciplinary study in which we used protein sequence analysis to shed light on animal evolution,” said Collins.
Humans played a key role in extinction
Previous studies of the egg fragments revealed that the shells had been cooked and discarded in fire pits. The charring on eggshell surfaces was enough evidence – indicating that the eggs were consumed by the first humans in Australia, roughly 65,000 years ago.
As per the hypothesis, this consumption could have also led to the extinction of the Genyornis bird 47,000 years ago.
“There is no evidence of Genyornis butchery in the archaeological record. However, eggshell fragments with unique burn patterns consistent with human activity have been found at different places across the continent,” said senior co-author Prof Gifford Miller from the University of Colorado, in a release.
“This implies that the first humans did not necessarily hunt these enormous birds, but did routinely raid nests and steal their giant eggs for food,” he said. “Overexploitation of the eggs by humans may well have contributed to Genyornis extinction.”
Solving the mystery about the origin of the ancient Aussie eggs might help scientists in the future to understand human evolution.