A cave dig in Indonesia has unearthed a unique collection of prehistoric ornaments and artworks that date back in some instances to at least 30,000 years ago. The site is thought to have been used by some of the world’s earliest cave artists.

Published today, our new findings challenge the long-held view that hunter-gatherer communities in the Pleistocene (“Ice Age”) of Southeast Asia were culturally impoverished.

They also imply that the spiritual lives of humans transformed as they encountered previously unknown species on the journey from Asia to Australia.

The human journey beyond Asia

Modern humans had colonised Australia by 50,000 years ago. It was a journey that required people crossing by boat from continental Eurasia into Wallacea, a vast swathe of island chains and atolls spanning the ocean gap between mainland Asia and Australia.

Adam Brumm , Author provided

Archaeologists have long speculated about the cultural lives of the first Homo sapiens to enter Wallacea, as part of the great movement of our species out of Africa.

Some have argued that human culture in the Late Pleistocene attained a high level of complexity as Homo sapiens spread into Europe and as far east as India. Thereafter, culture is thought to have declined in sophistication as people ventured into the tropics of Southeast Asia and Wallacea.

But new research in Wallacea is steadily dismantling this view.

New findings from ‘Ice Age’ Sulawesi

In the latest addition to this rash of discoveries, we describe a suite of previously undocumented symbolic artefacts excavated from a limestone cavern on Sulawesi, the largest island in Wallacea.

The artefacts were dated using a range of methods to between 30,000 and 22,000 years ago. They include disc-shaped beads made from the tooth of a babirusa, a primitive pig found only on Sulawesi, and a “pendant” fashioned from the finger bone of a bear cuscus, a large possum-like creature also unique to Sulawesi.

Michelle Langley and Adam Brumm/Bear cuscus bone image, Luke Marsden/Bear cuscus and babirusa, Shutterstock. , Author provided

Also recovered were stone tools inscribed with crosses, leaf-like motifs and other geometric patterns, the meaning of which is obscure.

Mark W Moore , Author provided

Further evidence for symbolic culture was shown by the abundant traces of rock art production gleaned from the cave excavations. They include used ochre pieces, ochre stains on tools and a bone tube that may have been an “air-brush” for creating stencil art.

(Top) Michelle Langley (bottom) Yinika Perston. , Author provided

All are from deposits that are the same age as dated cave paintings in the surrounding limestone hills.

It is very unusual to uncover buried evidence for symbolic activity in the same places where Ice Age rock art is found. Prior to this research, it also remained uncertain whether or not the Sulawesi cave artists adorned themselves with ornaments, or even if their art extended beyond rock painting.

Luke Marsden , Author provided

Early art and ornaments from Wallacea

Previous cave excavations in Timor-Leste (East Timor) have unearthed 42,000 year old shells used as “jewellery”, as reported in 2016. In 2014 archaeologists announced that cave art from Sulawesi is among the oldest surviving on the planet.

At one cave, a depiction of a human hand is at least 40,000 years old. It was made by someone pressing their palm and fingers flat against the ceiling and spraying red paint around them.

Next to the hand stencil is a painting of a babirusa that was created at least 35,400 years ago.

These artworks are compatible in age with the spectacular cave paintings of rhinos, mammoths and other animals from France and Spain, a region long thought to be the birthplace of modern artistic culture.

Some prehistorians have even suggested that the presence of 40,000-year-old art in Indonesia means that rock art probably arose in Africa well before our species set foot in Europe, although an Asian origin is also conceivable.

Based on the new evidence emerging from Timor and Sulawesi, it now appears that the story about early humans in Wallacea being less culturally advanced than people elsewhere, especially Palaeolithic Europeans, is wrong.

The weird world of Wallacea

Owing to the unique biogeography of Wallacea, the first modern humans to enter this archipelago would have encountered a strangely exotic world filled with animals and plants they had never imagined existed.

Surrounded by deep ocean troughs, the roughly 2,000 islands of Wallacea are extremely difficult for non-flying organisms to reach. Because of their inaccessibility, these islands tend to be inhabited by relatively few land mammals. Endemic lineages would have arisen on many islands as a result of this evolutionary isolation.

Sulawesi is the weirdest island of them all. Essentially all of the island’s terrestrial mammals, except for bats, occur nowhere else on earth. Sulawesi was probably where human beings first laid eyes on marsupials (cuscuses).

The discovery of ornaments manufactured from the bones and teeth of babirusas and bear cuscuses – two of Sulawesi’s most characteristic endemic species – implies that the symbolic world of the newcomers changed to incorporate these never-before-seen creatures.

Our excavations have unearthed thousands of animal bones and teeth, but only a tiny fraction are from babirusas. The near-absence of babirusas from the cave inhabitants’ diet, coupled with the portrayal of these animals in their art, and use of their body parts as “jewellery”, suggests these rare and elusive creatures had acquired particular symbolic value in Ice Age human culture.

Perhaps the first Sulawesians felt a strong spiritual connection with these odd-looking mammals.

This ‘social interaction’ with the novel species of Wallacea is likely to have been essential to the initial human colonisation of Australia with its unprecedentedly rich communities of endemic faunas and floras, including many species of megafauna that are now extinct.

In fact, elements of the complex human-animal spiritual relationships that characterise Aboriginal cultures of Australia could well have their roots in the initial passage of people through Wallacea and the first human experiences of the curious animal life in this region.