WELLINGTON, New Zealand -- The spade-toothed beaked whale is sorare that nobody has seen one alive, but scientists are sure the speciesexists.

Two skeletons were identified as belonging to the speciesafter a 17-foot whale and her calf beached themselves in New Zealand in2010. Scientists hope the discovery will provide insights into thespecies and into ocean ecosystems.

It was almost a missedopportunity, however, since conservation workers misidentified thecarcasses as a much more common type of whale and buried them.

In apaper published Tuesday in the journal "Current Biology," researchersfrom New Zealand and the United States say of their discovery: "For thefirst time we have a description of the world's rarest and perhaps mostenigmatic marine mammal."

Previously only three skull fragments ofthe species had been found: in New Zealand in 1872 and in the 1950s andthe last one 26 years ago on an island off Chile. The males have broadblade-like tusk teeth that give the species its name. Both males andfemales have beaks which make them resemble dolphins.

"This ispretty fantastic," said Ewan Fordyce, a geology professor at theUniversity of Otago who specializes in the evolution of whales and whowas not involved in the research. "There would be few, if any, mammalianspecies in the world that would be rarer. And we know much more aboutpanda bears and other iconic, rare animals."

The beached whales,an adult and her 11-foot male calf, were discovered on Opape Beach onthe North Island on New Year's Eve in 2010. Conservation workers thoughtthey were Gray's beaked whales and took tissue samples before buryingthem about nine feet under the sand.

Those samples ended up at theUniversity of Auckland where scientists did routine tests about sixmonths later. Rochelle Constantine, a co-author of the paper, said sheand her colleague Kirsten Thompson couldn't believe it when the resultsshowed the pair to be the rarest of whales.

"Kirsten and I went quiet. We were pretty stunned," she said.

Furthertests confirmed the discovery. Constantine said they then retestedabout 160 samples taken from other stranded Gray's whales but didn'tfind any more that had been misidentified.

This year, researchers returned to the beach to exhume the skeletons.

Antonvan Helden, who manages the marine mammals collection for New Zealand'snational museum Te Papa, said it wasn't a straightforward task to findthe remains after so long and that the mother's skull, which was buriedshallower than the rest of the remains, washed out to sea. But they wereable to recover the rest of the skeletons.

"It's a hugely significant find," said van Helden, a co-author of the paper.

Hesaid it's impossible to know why the whales came ashore although whalesoften beach themselves when they become ill. He said almost nothing isknown about the species except they live in the South Pacific Ocean andeat primarily squid.

Fordyce said it may be possible to use theskeletons of the rare whales to reconstruct their muscles and tissuesand to find out more about how they live and die and why they are soreclusive.

The scientists say the discovery could also provide broader insights into the ocean's complex ecosystems.

"This is good reminder," said Constantine, "of how large the oceans are, and of how little we know about them."