HOMO FLORESIENSIS (left) and H. sapiens (right)

More on this story from Scientific American.com:
Digging Deeper: Q&A with "Flores Man" discoverer Peter Brown

From Nature:
Flores Man
News@nature.com brings you the inside story on the discovery that will change our view of human evolution.

PETER BROWN

In what is being hailed as one of the most spectacular paleoanthropological finds of the past century, researchers have unearthed the remains of a dwarf human species that survived on the Indonesian island of Flores until just 13,000 years ago. The discovery significantly extends the known range of physical variation in our genus, Homo, and reveals that H. sapiens shared the planet with other humans much more recently than previously believed.

Scientists writing today in Nature describe a partial skeleton from a limestone cave on the island known as Liang Bua. Dubbed LB1, the specimen appears to have belonged to an adult female who stood barely a meter tall and had a skull the size of a grapefruit--the smallest member of the human family yet. Although closer in overall size to the much older australopithecines, such as Lucy, the new hominid apparently resembles members of the genus Homo in features related to chewing and upright-walking. Discoverers Peter Brown of the University of New England in Armidale, Australia, and his colleagues assign LB1 to a new species of Homo, H. floresiensis. They further propose that it was a dwarfed descendant of H. erectus, which is thought to have arrived in Southeast Asia by around 1.7 million years ago.

Dwarfing is well known to occur in island-dwelling mammals larger than rabbits, presumably because islands tend to have limited food supplies. Indeed, H. floresiensis wasn't the only miniature on Flores: pint-size bones of an elephant relative known as Stegodon have turned up at Liang Bua as well. Islands can also breed giants, however, and Liang Bua has yielded evidence of these as well, including Komodo dragons and very large rodents.

Just as astonishing as H. floresiensis's small size are the tools it is said to have used. In a second report in Nature, Michael Moorwood, also at the University of New England, and his collaborators describe stone artifacts found in association with the hominid remains. Most are simple flake tools, but the researchers also found points, perforators, blades and microblades that they say were most likely hafted as barbs. These more advanced tools--comparable in their complexity to those known to have been crafted by H. sapiens--turned up amidst baby Stegodon bones, suggesting to the team that this tiny human was hunting tiny elephants.

An isolated arm bone found deeper in the Liang Bua deposit, as well as the remains of several other individuals recovered more recently, indicate that H. floresiensis had a long history on the island, and was present there 95,000 years ago. This bantam human therefore significantly overlapped in time with Homo sapiens, who arrived in the region sometime between 55,000 and 35,000 years ago. How they interacted, however--if they ever even met face to face--remains a mystery.

Future work, team members say, will focus on trying to find large-bodied ancestors of H. floresiensis on Flores. They also plan to investigate other Indonesian islands, such as Java and Sulawesi. "Perhaps the far-flung Indonesian islands have acted as a series of independent 'Noah's Arks,' each with their own trademark endemic dwarfs and giants," comments team member Bert Roberts of the University of Wollongong in New South Wales. "In this regard, no amount of navel-gazing and hypothesizing can substitute for dogged field work, because only by excavating deposits will surprises such as Flores man be brought to light."