New Zealand's iconic kiwi -- a diminutive, flightless bird -- doesn't share an ancestor with the similar Australian emu as previously believed, researchers say. In fact, it's more closely related to an extinct 9-foot-tall bird that once roamed Madagascar, 7,000 miles away.

DNA testing showed the giant elephant bird, the biggest, heaviest bird that ever lived, was in fact the kiwi's closest relative -- at least until it went extinct sometime in the 17th century.

"Which is about as bizarre a finding as we could get," says New Zealander Alan Cooper, who has been researching the kiwi and its origins for almost 25 years.

Kiwis belong to a group of flightless birds known as ratites, which also includes emus, rheas, ostriches, cassowaries, and the now-extinct moas of New Zealand and the elephant birds of Madagascar.

"If I had to guess of all the ratite birds which one the Madagascan elephant bird was going to be closely related to, the kiwi would have been the last, by a mile," Cooper says.

Ratites are only found in the globe's southern hemisphere, with most scientists believing they originated on the supercontinent of Gondwana, before its breakup between 130 million and 50 million years ago, after which the species began to evolve separately.

That's why the elephant bird and the kiwi are related, even though New Zealand and Madagascar -- once joined in Gondwana -- are now thousands of miles apart.

Once roaming throughout Madagascar, about 200 miles off the southeastern African coast, it is unclear exactly why the elephant birds went extinct, although many scientists suspect human activity as a major cause.

The giant birds, which could weigh almost 800 pounds, laid eggs that could be more than three feet in circumference and more than a foot long.

Kiwis, by comparison, are about the same size as a domestic chicken, and are in fact the smallest of all living ratites.

Despite their small size, they lay the largest eggs -- in relation to body size -- of any bird species anywhere on the globe.

Of the five species of kiwi living in New Zealand, two are classified as vulnerable, one endangered, and one critically endangered, mostly as a result of deforestation of their native habitats.