In a breathtaking discovery, scientists working on a remote Indonesian island say they have uncovered the bones of a human dwarf species marooned for eons while modern man rapidly colonized the rest of the planet.
One tiny specimen, an adult female measuring about 3 feet tall, is described as "the most extreme" figure to be included in the extended human family. Certainly, she is the shortest.
This hobbit-sized creature appears to have lived as recently as 18,000 years ago on the island of Flores, a kind of tropical Lost World populated by giant lizards and miniature elephants.
She is the best example of a trove of fragmented bones that account for as many as seven of these primitive individuals. Scientists have named the new species Homo floresiensis (search), or Flores Man. The specimens' ages range from 95,000 to 12,000 years old.
The discovery has astonished anthropologists unlike any in recent memory. Flores Man (search) is a totally new creature that was fundamentally different from modern humans. Yet it lived until the threshold of recorded human history, probably crossing paths with the ancestors of today's islanders.
"This finding really does rewrite our knowledge of human evolution," said Chris Stringer, who directs human origins studies at the Natural History Museum in London. "And to have them present less than 20,000 years ago is frankly astonishing."
Flores Man was hardly formidable. His grapefruit-sized brain was about a quarter the size of the brain of our species, Homo sapiens. It is closer in size to the brains of transitional prehuman species in Africa more than 3 million years ago.
Yet evidence suggests Flores Man made stone tools, lit fires and organized group hunts for meat.
Just how this primitive, remnant species managed to hang on is unclear. Geologic evidence suggests a massive volcanic eruption sealed its fate some 12,000 years ago, along with other unusual species on the island.
Still, researchers say the perseverance of Flores Man smashes the conventional wisdom that modern humans began to systematically crowd out other upright-walking species 160,000 years ago and have dominated the planet alone for tens of thousands of years.
And it demonstrates that Africa, the acknowledged cradle of humanity, does not hold all the answers to persistent questions of how — and where — we came to be.
"It is arguably the most significant discovery concerning our own genus in my lifetime," said anthropologist Bernard Wood of George Washington University, who reviewed the research independently.
Discoveries simply "don't get any better than that," proclaimed Robert Foley and Marta Mirazon Lahr of Cambridge University in a written analysis.
To others, the specimen's baffling combination of slight dimensions and coarse features bears almost no meaningful resemblance either to modern humans or to our large, archaic cousins.
They suggest that Flores Man doesn't belong in the genus Homo at all, even if it was a recent contemporary. But they are unsure how to classify the species.
"I don't think anybody can pigeonhole this into the very simple-minded theories of what is human," anthropologist Jeffery Schwartz of the University of Pittsburgh. "There is no biological reason to call it Homo. We have to rethink what it is."
Details of the discovery appear in Thursday's issue of the journal Nature.
Researchers from Australia and Indonesia found the partial skeleton 13 months ago in a shallow limestone cave known as Liang Bua. The cave, which extends into a hillside for about 130 feet, has been the subject of scientific analysis since 1964.
The female skeleton and fragments from the six other individuals are being stored in a laboratory in Jakarta, Indonesia. The cave, which now is surrounded by coffee farms, is fenced off and patrolled by guards.
Near the skeleton were stone tools and animal remains, including teeth from a young stegodon, or prehistoric dwarf elephant, as well as fish, birds and rodents. Some of the bones were charred, suggesting they were cooked.
Excavations are continuing. In 1998, stone tools and other evidence found on Flores suggested the presence 900,000 years ago of another early human, Homo erectus (search). The tools were found a century after the celebrated discovery in the 1890s of big-boned H. erectus fossils in eastern Java.
Now, researchers suggest H. erectus spread to remote Flores and throughout the region, perhaps on bamboo rafts. Caves on surrounding islands are the target of future studies, they said.
Researchers suspect that Flores Man probably is an H. erectus descendant that was squeezed by evolutionary pressures.
Nature is full of mammals — deer, squirrels and pigs, for example — living in marginal, isolated environments that gradually dwarf when food isn't plentiful and predators aren't threatening.
On Flores, the Komodo dragon (search) and other large meat-eating lizards prowled. But Flores Man didn't have to worry about violent human neighbors.
This is the first time that the evolution of dwarfism has been recorded in a human relative, said the study's lead author, Peter Brown of the University of New England in Australia.
Scientists are still struggling to identify its jumbled features.
Many say its face and skull features show sufficient traits to be included in the Homo family that includes modern humans. It would be the eighth species in the Homo category.
George Washington's Wood, for example, finds it "convincing."
Others aren't sure.
For example, they say the skull is wide like H. erectus. But the sides are rounder and the crown traces an arc from ear to ear. The skull of H. erectus has steeper sides and a pointed crown, they said.
The lower jaw contains large, blunt teeth and roots like Australopithecus, a prehuman ancestor in Africa more than 3 million years ago. The front teeth are smaller than modern human teeth.
The eye sockets are big and round, but they don't carry a prominent browline.
The shinbone in the leg shares similarities with apes.
"I've spent a sleepless night trying to figure out what to do with this thing," said Schwartz. "It makes me think of nothing else in this world."