WELLINGTON, Dec. 17 (Xinhua) -- New Zealand's iconic flightless bird the kiwi, after which the people call themselves, might actually have come from Australia, New Zealand and Australian paleontologists said Tuesday.
The nocturnal bird was not a dwarf version of a distant ancestor, but more likely evolved from a tiny bird that could have flown from New Zealand's trans-Tasman neighbor and rival, according to the study by scientists from Australia's Flinders University and New Zealand's national museum Te Papa and Canterbury Museum.
The findings were based on a fossil found three years ago in central Otago on the east of the South Island, according to a joint statement from the three institutions.
The study results were supported by the genetic evidence that the kiwi was related to the Australian emu and not the New Zealand moa, an enormous emu-like bird that became extinct some 700 years ago, Dr Trevor Worthy, of Flinders University, said in the statement.
"One of the distinguishing attributes of the kiwi is that it lays an enormous egg, which is about a quarter of the bird's body weight and occupies most of the bird," said Worthy, an internationally-recognized expert on the moa.
The findings overturned a commonly held theory championed by the late eminent evolutionary biologist Stephen Jay Gould in his 1986 essay, which sought to explain the kiwi egg's size by promoting the idea that the kiwi was highly derived from a large moa-like ancestor.
"This fossil from the early Miocene, about 20 million years ago, shows us that it's a tiny bird about one third of the size of a small kiwi today. It suggests the opposite is, in fact, the case that the kiwi has developed towards a larger size, a trend that is seen in many birds from the early Miocene," Dr Paul Scofield, of Canterbury Museum, said in the statement.
"And if, as the DNA suggests, the kiwi is related to the emu, then both shared a common ancestor that could fly. It means they were little and had wings, and that they flew to New Zealand," he said.
"We need to find wing bones to put the theory beyond all doubt. "
The researchers planned to continue excavations this southern summer.