A hand stencil discovered on a cave wall in Indonesia is prompting a reevaluation of early human migration patterns across Southeast Asia. Dated to at least 67,800 years ago, the image is currently the oldest known example of rock art in the region, suggesting human presence along a crucial island corridor toward Australia significantly earlier than previously understood.
Dating the Cave Art
The faded stencil was found at Liang Metanduno on Sulawesi, surrounded by more recent paintings. Researchers at Griffith University used uranium-series dating to analyze mineral layers that formed over the paint, effectively using the radioactive decay of uranium into thorium as a timeline. Because the mineral crust formed *after* the painting, the resulting age is a conservative estimate.
A Hand Shaped on Purpose
Further examination revealed the hand stencil wasn’t simply a natural impression. After the initial image was created using pigment, someone deliberately narrowed the finger outlines, transforming the print into a more defined, claw-like shape. While hand stencils are found globally, this modified style has so far been unique to Sulawesi.
Cave Art Made Over Millennia
The cave wall shows evidence of repeated artistic activity over an extraordinary period. Mineral layers indicate separate painting episodes spaced by at least 35,000 years, with activity continuing until around 20,000 years ago. Later paintings were even applied over surfaces where older limestone layers had eroded, partially exposing the original stencils.
Routes Across Ancient Seas
The discovery is particularly significant because the cave is located near a proposed route for early human migration into the Australia-New Guinea landmass. Debate exists regarding the timing of this arrival, with estimates ranging from around 50,000 years ago to well over 60,000 years ago. According to study lead author Maxime Aubert, the findings “underscore the archaeological importance of the many other Indonesian islands between Sulawesi and westernmost New Guinea.”
Linking Caves to Australia
Archaeological evidence from Madjedbebe in northern Australia places humans there approximately 65,000 years ago, based on stone tools and red pigment. The Sulawesi hand stencil helps refine understanding of which islands were occupied *before* that arrival, as creating art requires both people and the resources to make pigment. However, researchers caution that the Sulawesi artists are best understood as possible ancestors, not direct founders.
Interpreting the Handmakers
Identifying the specific human group responsible for the stencil is complex, as Sulawesi was once inhabited by multiple kinds of early humans, referred to as hominins. The team believes the stencil was likely created by our species, Homo sapiens, due to the intentional modification of the fingers, a behavior commonly associated with our ancestors. However, further evidence – such as nearby bones, tools, or camps – is needed to confirm this.
Fragile Walls, Lasting Signals
The cave art is under threat from chemical weathering, particularly salt crystal growth within the porous rock. This process is accelerating, and field teams have documented increasing damage in recent decades. Protecting this ancient art requires stabilizing the cave’s microclimate and limiting further disturbance.
Frequently Asked Questions
How was the age of the hand stencil determined?
Researchers used uranium-series dating, analyzing the radioactive decay of uranium into thorium within mineral layers that formed over the paint. This method provides a conservative minimum age for the artwork.
What is unique about the hand stencil found in Sulawesi?
The hand stencil is the oldest known example of rock art in the region, dating back at least 67,800 years. Additionally, the fingers of the stencil were deliberately narrowed, a style unique to Sulawesi.
Does this discovery prove that people traveled directly from Sulawesi to Australia?
The discovery suggests that people were present along a key island corridor toward Australia much earlier than previously thought, but it does not definitively prove which route they took. A southern route through Timor remains a possibility.
Considering the fragility of these ancient artworks and the ongoing threat of erosion, what steps might be taken to ensure their preservation for future generations?
