A new human species recently discovered on the island of Flores in Indonesia, dating from a mere 13 000 years ago, and remarkable for being only one metre tall. Details have just been published in Nature. It is being described as one of the most important and sensational palaeontological finds in decades.

Flores is across Wallace's Line from mainland Asia: that is, it has always been across a deep oceanic barrier regardless of fluctuating sea levels. This seems to mean that this tiny creature must have had the intelligence to make some form of raft or boat.

Homo floresiensis therefore also co-existed with our own human species, and modern inhabitants of Flores have legends of a hairy little people they call Ebu Gogo. Well, so do many peoples around the world; this does not mean much by itself, but with this discovery we now know there could be truth in these legends at least on Flores. Their legends are not just of the ancient past either: they speak of Ebu Gogo existing at the time of the Dutch colonisation, several hundred years ago, and possibly as recently as 1900. There are legends of still-extant apelike creatures on other islands, such as the orang pendek of Sumatra.

Scientists have also dubbed these creatures hobbits, a name that is sure to stick in the headlines.

Indonesian and Australian archaeologists working in limestone caves at Liang Bua found a one-metre female specimen, dubbed LB1, in September 2003. At first they assumed it was a juvenile, but wear on the teeth and growth lines on the skull confirmed it was adult. It walked upright, and had longer than expected arms. The arms haven't been fully studied yet, but may indicate it also used the trees. As Flores is home to the ravenous Komodo dragon, hiding in trees might have had survival value.

LB1 was dated to 18 000 years ago, but later discoveries of more individuals has brought the date of occupation closer. The remains are recent enough that they are good candidates for retrieving DNA to analyse their place in our family tree: it is speculated that they evolved from Homo erectus, which they resemble in skull and tooth shapes. The earliest fragments found are between 95 000 and 74 000 years old. There was a volcanic explosion on Flores 12 000 years ago: if they went extinct then, around about the time of the latest known fragment, that and competition from modern humans might have done them in.

The caves contain a few stone tools dated from about the same period, and some animal bones show signs of charring by fire. There is at present no evidence that contemporary Homo sapiens inhabitants of Flores used the caves at the same time. If not, H. floresiensis shared these two sapient abilities.

The brain size of H. floresiensis was (or is, if they're still lurking in the dense unexplored forests of Indonesian islands) about 380 cm3, like that of a chimpanzee, or a modern human baby. (An adult human brain can be four times as big.)

Islands produce strange size effects. You get both giants and pygmies. Cyprus had its pygmy hippopotamus and elephant, Wrangel Island its pygmy mammoth, but Mauritius had the dodo and Flores and Komodo have their gigantic top-predator lizard.

Later, there has been the inevitable casting of doubts on the original results. Some people have suggested the type specimen, the only reasonably full skeleton, is that of a microcephalic Homo sapiens, and the other remains are within sapiens range of sizes. There is also a bit of kerfuffle about who actually gets to keep the bits. New analysis in September 2005 of further remains of varying ages seems to confirm that the specimens do constitute a dwarfish race, not a few microcephalic individuals who happened to survive.

New Scientist, 30 October 2004
New analysis, September 2005: http://news.bbc.co.uk/2/hi/science/nature/4331252.stm