"Hobbit" human was dated incorrectly

Homo floresiensis lived about 40, 000 years earlier than previously thought

Skull of Homo floresiensis: It is unusually small for a early man who lived almost at the same time as Homo sapiens. © Ryan Somma / CC-by.sa 2.0
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The puzzlingly short-lived "Hobbit" man from the Indonesian island of Flores was obviously not a contemporary of modern man. He died about 50, 000 years ago - much earlier than previously thought, as revealed by new excavations and dating of material from the cave. But this throws a whole new light on the classification of this enigmatic human type, as the researchers report in the journal "Nature".

The fossils of Homo floresiensis, discovered some ten years ago in a cave on the island of Flores, remain a mystery to this day. In his small growth and the small brain volume, he resembles the Homo erectus, dating determined the age of this unknown human type but only 18, 000 to 12, 000 years - he would therefore have lived at the same time with the modern Homo sapiens.

Due to these discrepancies, it has been argued for years whether the "hobbit" people were a separate human species or simply suffered from a genetic defect or even Down's syndrome.

Excavations in the cave of Homo floresiensis © Liang Bua Team

Disturbed layer sequence

A discovery by Thomas Sutikna of the University of Wollogong in Australia and his colleagues sheds more light on the subject - and raises new questions. In their study of the underground in the cave of the "Hobbits" they found out that the sequence of geological strata is more disturbed than it was assumed some ten years ago.

"As we expanded our excavations, it became increasingly clear that there was a large pedestal of older deposits that was broken by an erosion area containing recent sediments, " explains Sutikna. When the archologists collected coal samples for dating, they did not take them directly next to the bones, but from another part of the supposedly same geological layer. display

Wrong dated

But as it turns out, this was a mistake: The bones of Homo floresiensis come from the "pedestal" and thus the older part of the rock layers in the cave floor. The dated bits of coal, however, come from the younger, subsequently deposited sediment layer, as Sutikna and his colleagues report. Their age therefore can not reflect the age of Homo floresiensis.

For the geological investigation of the rock strata, the researchers dug well eight meters deep into the cave floor. Liang Bua team

To find out what time the skeletal fragments actually came from, the researchers re-dated the rock at the site with modern luminescence methods and subjected bone samples from three forearm bones of Homo floresiensis to a uranium-thorium dating. The result: The skeletons are therefore already between about 100, 000 and 60, 000 years old, the last stone tools of Hobbit people were dated to 50, 000 years, as the researchers report.

No neighbor of Homo sapiens?

But that means that the Hobbit people lived almost 40, 000 years earlier than previously thought and that they probably were not contemporaries of anatomically modern humans in their region. Because they only started to migrate from the Asian mainland to the islands of Indonesia some 50, 000 years ago. At this time, however, Homo floresiensis may have been extinct.

"Whether the 'hobbits' met with modern humans or other groups of people as they spread across Southeast Asia remains an open and exciting question, " says Roberts. He and his colleagues hope that future finds will further illuminate the history of the Hobbit people and their neighbors. (Nature, 2016; doi: 10.1038 / nature17179)

(Nature, 31.03.2016 - NPO)