Despite moa being extinct for about 500 years, scientists are still unravelling how the flightless giants evolved.
Research published today in Molecular Biology and Evolution shows that New Zealandmoa were closely related to South American tinamous, which are able to fly.
The results bolster research that suggests moa ancestors flew to New Zealand and then lost the ability to fly.
Flightless ratites are widely spread - ostriches in Africa, rheas in South America, emus and cassowary in Australia, and kiwi and the extinct moa in New Zealand.
To explain that distribution, it had been thought that ratites were on the super-continent Gondwana before it began to break apart about 85 million years ago.
New Zealand scientist Allan Baker led the research, which used DNA from the extinct little bush moa to compare with other ratites.
The family tree showed moa were most closely related to tinamous, suggesting they had lost the ability to fly after arriving in New Zealand.
Mike Dickison, who has studied flightless birds, said the "big issue" was that ratites were assumed to be flightless and were "stranded on Gondwana as it broke apart".
"Now it seems they flew around the continents and went flightless independently," he said.
"Some might think it's a bit implausible for flightlessness to happen so many times, but it's super-common, at least among some groups.
"Just about every island in the Pacific had its own species of flightless rail, and it looks like ratites are as prone to going flightless as rails are."
A 20-million-year-old kiwi fossil found in Central Otago created a stir last year, with researchers suggesting kiwi flew here from Australia long after Gondwana broke apart.
- The Press
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