Excavation indicates a major ancient migration to Timor Island

Four stone cutting blades made from chipped rock
Four stone cutting blades made from chipped rock

New archaeological evidence indicates that humans first reached the island of Timor in large numbers, challenging scientists’ understanding of how ancient people migrated from Southeast Asia to Australia, according to a new study led by a UCL researcher.

The study, published in Nature Communications , dated and analysed ancient sediment, artefacts, and animal remains discovered in a large rock overhang in Laili, located in north-central Timor-Leste (East Timor). The researchers found a distinct ’arrival signature’ dating to about 44,000 years ago, indicating there were no humans on the island before then.

These dates, combined with findings from other sites in Timor-Leste and nearby Flores Island, show that humans were largely absent from Timor and the nearby islands when there were already people living in Australia. This means that the first settlers of Australia likely used New Guinea instead of Timor as a stepping stone to reach the continent.

Lead author, Dr Ceri Shipton (UCL Institute of Archaeology) said: "This finding represents a significant change to our understanding of ancient human migration across the Malay Archipelago and into Australia. Tracing the ancient journeys of our ancestors is a major challenge, but this new evidence shows that there was a particularly intensive migration across the southern islands soon after 50,000 years ago."

The research team, composed of archaeologists from UCL, the Australian National University (ANU), Flinders University, and the ARC Centre of Excellence for Australian Biodiversity and Heritage, excavated deposits deeply buried in the rock overhang. There, they unearthed thousands of small stone tools, as well as charcoal, ashes, and charred fish bones.

The team carefully dated layers of sediment with embedded artefacts, as well as the underlying natural layer using both carbon dating and Optically Stimulated Luminescence, a technique to tell when sand grains were last exposed to light. They found that the first stone tools were found in a layer dating back about 44,000 years ago, well after the initial settlement of Australia.

Co-author Professor Sue O’Connor, from ANU, said: "The absence of humans on Timor Island earlier than at least 50,000 years ago is significant as it indicates that these early humans arrived on the island later than previously believed. This provides further evidence to suggest early humans were making the crossing to Australia using the stepping stone island of New Guinea, rather than Timor Island as researchers had previously suggested."

Precisely dating human’s first arrival to Timor has long proved difficult because most caves on the island lack the kind of layered sediments that preserve without human occupation. However, unusually for the region, the overhang in Laili does contain layers of natural sediments and deposits from as far back as 59,000 years ago. Other stone tools have been found in caves around the island, but most have been found atop bedrock meaning the time before their appearance couldn’t be reliably dated, and their initial arrival signature was mixed with later tools.

What also stood out the researchers was the large volume of artifacts recovered at Laili. The sudden appearance in sediment layers and sheer number of artefacts found at the site indicate that migration to Timor was quick, massive and was likely a major concerted colonisation effort. There was also a particular focus on fish and shellfish in the diet of the first settlers, an aquatic diet that is easily transferred between islands, unlike the unique land resources different islands have to offer.

Co-author, Dr Shimona Kealy from ANU, said: "The traditional view held by researchers is that early humans who were making these significant water crossings were stumbling upon these islands by mistake, largely because it was so long ago. Their arrival on Timor was no accident. This was a major colonisation effort, evident through the sheer number of people who were making the journey. It’s a testament to these peoples’ level of maritime technology and the boats they created, but also their confidence and competence in braving maritime crossings."

Strong ocean currents on the western side of the island may have been an obstacle to earlier colonisation of Timor for people emigrating from Southeast Asia. Instead, early humans seemed to have passed Timor by to settle New Guinea farther east and then Australia to the south, before a later migration wave arrived on Timor.

This research was supported by the Australian Research Council.

    Mike Lucibella

    • E: m.lucibella [at] ucl.ac.uk

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