* Tree new to science found in Ethiopian conflict zone
* Hints at overlooked plant, animal species to be found
OSLO, April 23 (Reuters) - A tree that covers a large area of eastern Ethiopia but has only recently been categorised by botanists raises hope for finding new species elsewhere, experts said.
The acacia fumosa tree, which grows in an area the size of the island of Crete, was not "found" for scientific purposes until 2006-7, mostly likely because its main habitat is a war zone.
"I have spent a lifetime looking at plants and describing species -- it knocked me sideways when I heard about this tree," David Mabberley of the Royal Botanic Gardens in Kew, England, told Reuters.
"The total numbers must be in the millions," he said of the pink-flowered, 6-m (20-ft) tall tree that covers hillsides in an inaccessible area of 8,000 sq kms (3,100 sq miles) near the border with Somalia.
In an article in Friday's edition of the journal Science, he wrote that the tree had been overlooked by generations of botanists, apparently because of few visits to the area where the Ogaden National Liberation Front is fighting for autonomy.
The discovery was an encouraging sign that other overlooked large species might still be found, from rainforests to the ocean depths. Still, he said, scientists were "highly unlikely" to find another tree dominating such a large area.
The discovery contrasts with gloom about destruction of habitats and global warming threatening more extinctions. Environment Ministers of the Group of Eight are meeting in Italy from April 22-24 discussing ways to slow a loss of biodiversity. "It's an upbeat story for a change," Mabberley said. The tree was found by Swedish botanist Mats Thulin and previously described in a Nordic journal.
People in the sparsely populated region did not exploit the tree except for firewood but it might have commercial uses, for instance in gum used for foodstuffs or glues.
About 10,000 new species of plants or creatures are described worldwide every year, most of them tiny, he said.
Among exceptions, a coelacanth fish known only from fossils was caught off South Africa in 1938. The wollemi pine, also known from fossils, was found in Australia in 1994. And the saola antelope in Vietnam and Laos was identified in 1992.
"I suspect there are still large species out there to be discovered," Craig Hilton-Taylor, head of the International Union for Conservation of Nature's Red List of endangered species, told Reuters.
He said that countries that have suffered conflicts -- such as Democratic Repubic of Congo, Cambodia or Colombia -- were likely places to find overlooked species.
And some types of beaked whales that dive to great depths were only known from washed up corpses. "There are probably still a few things in the deep ocean we haven't found," he said.
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Editing by Michael Roddy
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