Ancient stone tools with a mystery maker

Stone tools dating back to at least 118,000 years ago have been discovered in Sulawesi, Indonesia, suggesting that early humans colonised the island much earlier than previously thought, Australian researchers write in a paper published in Nature.

These tools predate the arrival of modern humans, suggesting that the island may have initially been inhabited by an archaic human species. However, the absence of human fossils of this age on the island means that the identity of the tool-makers — and which human-like species was the first to arrive at Sulawesi — remains unknown.

An enigmatic hominin group colonized the Indonesian island of Flores at least one million years ago. By 50,000 years ago, modern humans (Homo sapiens) had crossed to Sahul, the landmass composed of Australia and Papua. Sulawesi, the largest and oldest of a group of islands separating continental Asia from Sahul, is thought to have had a key role in these dispersals, and prior research has shown that modern humans were living on the island at least 40,000 years ago.

Lead author Gerrit van den Bergh from the University of Wollongong and colleauges discovered the artifacts at four new sites when they conducted excavations near the village Talepu in the southern part of Sulawesi.

The authors suggest that other islands in the region may also contain undiscovered records of early humans, which could fill in some of the gaps in our knowledge of ancient hominin diversity in the region.