Cave paintings in remote mountains in Borneo have been dated to at least 40,000 years ago, and include a painting of what seems to be a local species of wild cattle - possibly the world's oldest dated example of figurative art.
     Indonesian and French archaeologists discovered a vast assemblage of prehistoric artworks in limestone caves atop densely forested peaks in the remote interior mountains of East Kalimantan in the 1990s - rare paintings of animals, but thousands of hand stencils - yet little other evidence for human occupation in the caves.
     The team proposed at least two distinct phases of art production, the first characterised by reddish-orange hand stencils and large figurative paintings of animals, and a later phase characterised by dark purple hand stencils. During this phase the artists also painted tattoo-like designs on the wrists, palms, and fingers of some, and some were linked by motifs resembling tree branches or vines.
     In the early 2000s the team dated part of a cave formation that had grown over the top of a hand stencil. Their results implied an age of at least 10,000 years for the underlying artwork.
     A recent paper suggests the paintings are far older. Uranium-series dates obtained from calcium carbonate samples collected in association with cave art from six sites provides the first reliable estimates for the approximate date of rock art production.
     The earliest image is a large reddish-orange painting of an animal similar to the wild banteng still found in the jungles of Borneo, and has a minimum age of 40,000 years. The reddish-orange hand stencils are similar in age, suggesting the first rock art style appeared between about 52,000 and 40,000 years ago. The oldest dark purple paintings date to about 21,000 to 20,000 years ago. A human figure this colour was created at least 13,600 years ago. These dates imply a major change within Borneo's rock art culture about 20,000 years ago during the Last Glacial Maximum.
     Similar rock art appeared around 40,000 years ago in the Maros caves of Sulawesi, a vital stepping-stone between Asia and Australia just across the Makassar Straight west of Borneo. Sulawesi has never been connected to the nearby Eurasian continent. Borneo is now Earth's third-largest island, but for most of the ice age it was connected to Eurasia.

Edited from The Conversation (7 November 2018)