Sulawesi: Primeval tools are riddles

Researchers discover more than 100, 000 years old stone blades of unknown origin

Stone tools like these made unknown toolmakers on Sulawesi more than 100, 000 years ago. © Erick Setiabudi
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Who was the toolmaker? On the island of Sulawesi, anthropologists have discovered primitive stone tools that are unlikely to exist. Because the blades are already 200, 000 to 100, 000 years old and thus come from a time when there were no people on the island - so at least that's what they thought. Who created these tools - whether a human cousin, the Homo erectus or even the enigmatic hobbit people, remains so far open, as the researchers report in the journal "Nature".

According to popular theory, the Homo sapiens colonized Australia and the islands east of Borneo only about 50, 000 years ago. In fact, rock art in Northwest Sulawesi attests to the presence of Homo sapiens around 40, 000 years ago, but other, older mankind's testimonies have not existed there. However, the enigmatic "hobbit man" Homo floresiensis could have arrived on the neighboring island of Flores a million years ago.

Settled already some 100, 000 years ago?

Now new finds on Sulawesi provide further guesswork. During excavations in the south of the island discovered Gerrit van den Bergh of the University of Wollongong and his colleagues amazing old stone blades and tools. A uranium dating of animal bones and teeth from the layer below finds evidence for an age of around 200, 000 years. An analysis of sediment samples indicates the emergence of stone tools in the period from 194, 000 to 118, 000 years ago.

During the excavations on Sulawesi. © Dida Yurnaldi

The primitive shape of the stone tools also fits in with this old age: they consist of simple tees of larger stones, which were produced by blows with a hammer-like chunk. "Although a pattern can be seen in the art, there is little evidence that the creators of these stone blades wanted to give their tools a special shape, " the researchers explain. "Instead, they simply wanted to produce sharp-edged cutting by knocking it off."

Who were the toolmakers?

"From these results, we conclude that the first settlement of Sulawesi must have occurred at least 118, 000 years ago, " say van den Bergh and his colleagues. But that means there must have been people in this region long before Homo sapiens came here on the way to Australia. But who then were the mysterious creators of stone tools? display

Also on the Walanae River east of the site were primitive stone tools found, but they are younger. Gerrit van den Bergh

Theoretically, there are three candidates for this, as the researchers explain: The early colonists could belong to Homo floresiensis, which has been living on the neighboring island of Flores for at least 190, 000 years. However, it would also be possible for representatives of Homo erectus to leave the tools behind, as relics of this ancestor already testify 1.5 million years ago from his presence on the island of Java to the west.

And finally, even the Denisova people, who have so far been proven only in Central Asia, could have extended their distribution area to the southeast.

The search continues

But whether one of these three candidates created the tools now discovered on Sulawesi - and which one of them - remains open for the time being. Because that can only be found out when human bones or teeth from this period are discovered on the island. Unfortunately, this evidence is missing so far, as the researchers report.

Apart from the stone blades and a few animal bones, the mysterious inhabitants of Sulawesis have apparently left little. However, palaeontologists hope that in the future they will be able to catch up on one of the neighboring islands. For they believe that these mysterious colonists have come with the ocean currents either from the north of the Philippines, or from the west adjacent Borneo. (Nature, 2016; doi: 10.1038 / nature16448)

(Nature, 14.01.2016 - NPO)