A team of archaeologists from Australia and Indonesia has discovered two figurative paintings of the Sulawesi warty pig (Sus celebensis) — a species of small (40 to 85 kg), short-legged pig with characteristic facial warts — in Leang Tedongnge and Leang Balangajia 1 caves on the Indonesian island of Sulawesi. The warty pig painting from Leang Tedongnge cave dates to at least 45,500 years ago, making it the earliest known representational work of art in the world.
The Sulawesi warty pig images at Leang Tedongnge and Leang Balangajia 1 were both executed in red or dark red/purplish mineral pigments (ochre).
In each instance, the animal depiction consists of a complete body outline of a pig shown in profile view.
Both figures are represented in immobile or static positions. The pictorial outlines are infilled with irregular patterns of painted lines and dashes.
The prehistoric artists did not clearly portray any primary sexual characteristics (e.g., genitalia and mammary glands) in the outline representations of the warty pigs.
At Leang Tedongnge cave, the pig figure is positioned on the rear wall of the cave.
Measuring 136 cm by 54 cm (53.5 by 21.3 inches), this motif is associated with two hand stencils situated above and close to the hindquarters of the pig representation. At least two or three other pig figures are located on the same panel.
“It shows a pig with a short crest of upright hairs and a pair of horn-like facial warts in front of the eyes, a characteristic feature of adult male Sulawesi warty pigs,” said Professor Adam Brumm, a researcher in the Australian Research Centre for Human Evolution at Griffith University.
“Painted using red ochre pigment, the pig appears to be observing a fight or social interaction between two other warty pigs.”
“Leang Tedongnge cave is in a valley that’s enclosed by steep limestone cliffs and is only accessible by a narrow cave passage in the dry season, as the valley floor is completely flooded in the wet,” he added.
“The isolated Bugis community living in this hidden valley claim it had never before been visited by Westerners.”
At Leang Balangajia 1 cave, the large red pig figure was painted on the ceiling of a small side chamber. This motif measures 187 cm (73.6 inches) in length and 110 cm (43.3 inches) in height.
There are possibly at least two other figurative animal motifs on the wall and ceiling of the chamber. They are very poorly preserved, however, and largely indistinct. Four hand stencils are superimposed on top of the large red pig figure.
“Humans have hunted Sulawesi warty pigs for tens of thousands of years,” said Basran Burhan, a Ph.D. student in the Australian Research Centre for Human Evolution at Griffith University.
“These pigs were the most commonly portrayed animal in the ice age rock art of the island, suggesting they have long been valued both as food and a focus of creative thinking and artistic expression”.
The result of Uranium-series dating provided respective minimum ages of 45,500 and 32,000 years for the Sulawesi warty pig images at Leang Tedongnge and Leang Balangajia 1.
“Rock art is very challenging to date,” said Professor Maxime Aubert, a researcher in the Griffith Centre for Social and Cultural Research at Griffith University.
“However, rock art produced in limestone caves can sometimes be dated using Uranium-series analysis of calcium carbonate deposits (cave popcorn) that form naturally on the cave wall surface used as a ‘canvas’ for the art.”
“At Leang Tedongnge, a small cave popcorn had formed on the rear foot of one of the pig figures after it had been painted, so when dated, it provided us with a minimum age for the painting.”
“It was this mineral deposit that was Uranium-series dated to yield an age of 45,500 years, indicating that the rock art scene had been painted sometime prior to this.”
The previously oldest dated rock art scene, at least 43,900 years old, was a depiction of hybrid human-animal beings hunting Sulawesi warty pigs and dwarf bovids, discovered by the same research team at a nearby limestone cave site.
“We have found and documented many rock art images in Sulawesi that still await scientific dating,” said Adhi Agus Oktaviana, a Ph.D. student in the Griffith Centre for Social and Cultural Research at Griffith University.
“We expect the early rock art of this island to yield even more significant discoveries.”
The rock art of Sulawesi now represents some of the earliest, if not the earliest, archaeological evidence for anatomically modern humans in Wallacea, a biogeographically distinct zone of oceanic islands situated between continental Asia and Australia.
“Our species must have crossed through Wallacea by watercraft in order to reach Australia by at least 65,000 years ago,” Professor Aubert said.
“However, the Wallacean islands are poorly explored and presently the earliest excavated archaeological evidence from this region is much younger in age.”
A paper on the findings was published in the journal Science Advances.
Adam Brumm et al. 2021. Oldest cave art found in Sulawesi. Science Advances 7 (3): eabd4648; doi: 10.1126/sciadv.abd4648