This article was originally published at The Conversation and has been republished under Creative Commons.
The dating of an exceptionally old cave painting of animals that was found recently on the Indonesian island of Sulawesi is reported in our recent paper.
The painting portrays images of the Sulawesi warty pig (Sus celebensis), which is a small (40–85 kilograms), short-legged wild boar endemic to the island.
Dating to at least 45,500 years ago, this cave painting may be the oldest depiction of the animal world, and possibly the earliest figurative art (an image that resembles the thing it is intended to represent), yet uncovered.
Ice age art in Indonesia
Sulawesi is host to abundant cave art, the existence of which was first reported in the 1950s.
Until recently, the prevailing view was this art was the handiwork of Neolithic farmers who arrived around 4,000 years ago from southern China rather than the hunter-gatherers who had lived on Sulawesi for tens of thousands of years.
We now know that this is not correct.
In 2014, we reported the first dates for the South Sulawesi rock art.
Based on uranium-series analysis of mineral deposits (calcite) that formed naturally on the art, we showed that a stenciled image of a human hand found in one cave was created at least 40,000 years ago. This is compatible in age with the famous ice age cave art in Europe.
Then, in 2019, we dated a spectacular painting at another cave that portrays hybrid human-animal figures hunting Sulawesi warty pigs and dwarf buffalos, anoas. This hunting scene is at least 43,900 years old, and it features what may be the oldest depictions of supernatural beings.
In our latest study, we push the age of Sulawesi’s rock art a little deeper into the past.
The secret valley
In December 2017, we conducted the first survey of an isolated valley set in mountainous terrain a stone’s throw from one of Indonesia’s largest cities, Makassar.
Despite its proximity to a major urban center, there is no road to this valley. The small community of local Bugis farmers live a secluded existence, although they are widely reputed for the sublime quality (and potency) of their palm wine, ballo.
According to them, no Westerner had ever set foot in their valley before.
This secret valley is a pristine environment and a place of resplendent natural beauty. There is hardly any rubbish in the tiny village in the center of the valley. Being there feels like stepping back in time.
The valley harbors a limestone cave known as Leang Tedongnge, and inside it, we found a rock painting the locals claimed they had never noticed before.
The painting was produced using a red mineral pigment (ironstone hematite, or ochre). It depicts at least three Sulawesi warty pigs engaged in social interaction of some kind.
We interpret the surviving elements of this artwork as a single narrative composition or scene, a mainstay of how we tell stories using images today but an uncommon feature of early cave art.
Unlocking the age of the art
Dating rock art is very difficult at the best of times. But at Leang Tedongnge, we were fortunate to identify a small calcite deposit (known as “cave popcorn”) that had formed on top of one of the pig figures (pig 1, below).
We sampled the calcite and analyzed it for uranium-series dating. Amazingly, the dating work returned an age of 45,500 years ago for the calcite, meaning the painting on which it formed must be at least this old.
Early art in Wallacea
Our discovery underlines the global importance of Sulawesi, and the wider Indonesian region, for our understanding of where and when the first cave art traditions developed by our species arose.
The great antiquity of this artwork also offers hints at the potential for other significant findings in this part of the world.
Sulawesi is the largest island in Wallacea, the zone of oceanic islands located between mainland Asia and the ice age continental landmass of Australia-New Guinea.
Modern humans are said to have crossed through Wallacea by watercraft at least 65,000 years ago in order to reach Australia by that time.
But the Wallacean islands are poorly explored, and presently, the earliest excavated archaeological evidence from this region is much younger.
We believe further research will uncover much older rock art in Sulawesi or on other Wallacean islands, dating back at least 65,000 years and possibly earlier.