WELLINGTON -- Part of a skeleton of an upland moa -- a flightless bird that has been extinct in New Zealand for about 500 years - has been found in a cave more than 1,100 meters up a mountain in the South Island, along with one of its eggs.

Brian Patrick, collections and research manager at Otago Museum, Dunedin, which revealed the discovery this week, dubbed it a "once-in-a-lifetime find".

The upland moa (megalapteryx didinus) was one of the smallest of the 11 species of moa known to have been plentiful in New Zealand from about 15 million years ago until they were hunted to extinction by the indigenous Maori people around the year 1500.

Standing about one-meter high, much shorter than the species that lived in the Lowlands, it was stockily built and unusually covered right down to its toes with feathers to help it tolerate the cold temperatures of the Southern Alps.

"It was very distinctive and must have been an amazing sight," DPA quoted Patrick as saying.

Scientists are excited at the find because although the museum has a large collection of moa skeletons, it had few bones of the upland species and little scientific research has been done on it.

Patrick said the remains would allow the museum to construct the first complete skeleton of the bird and give insights about its habitat and nesting behavior.

The bones were found by hunters in the Humboldt mountains range, named after the German scientist and explorer Baron Friedrich Alexander von Humboldt (1769-1859), at the head of Lake Wakatipu.

Realizing the bones were unusual, the two hunters carried them back to Dunedin to present to the museum.

Scientists will carbon-date the skeleton, identified as a female, and plan to fly to the area to pick up any remaining fragments and inspect the site.

But they will not be able to do this until October when snows from the Southern Hemisphere winter have melted.

A moa specialist, Trevor Worthy, said there had been no trace of the upland moa in the Humboldt mountains previously, although remains had been found in Takahe valley, in the Murchison mountains, about 100 kilometers to the south.