A cave on the island of Sulawesi, known as Leang Bulu Bettue, has been found to host thousands of personal ornaments and pieces of art dated to between 30,000 and 22,000 years ago. The discovery fills a major gap in our knowledge and refutes the curious belief that people living in the region lacked symbolic behavior.

Tothe first people whoreached Sulawesi, it must have seemed like another world. The largest island in Wallacea the section of the Indonesian archipelago that even during the Ice Ages was cut off from both the Asian and Australian continents by deep waters has plants and animals like nothing seen elsewhere. As a paper in Proceedings of the National Academy of Sciences notes: It was probably on Sulawesi that H. sapiens first encountered marsupials.

Yet we know almost nothing about how these people responded upon finding themselves in a place so unlike anything humans had encountered before. Few records of their symbolic culture, as opposed to practical things like stone tools, have been found. As recently as two years ago, it was argued that this absence reflected a lack of such symbolism, implying that the first peoples of the region were far less culturally advanced than their contemporaries in Africa or western Asia.

First author Dr Adam Brumm of Griffith University, however, is convinced we haven’t found such examples of symbolic behavior because we haven’t looked hard enough, noting that most of Wallecea’s islands have not been studied at all in searches for early human artifacts.

Brumm told IFLScience that extensive rock art has been found on Sulawesi. I thought it was just a matter of time before ornamental art was found, he said. The urge to decorate is universal, but the form was surprising.

Marine body adornment, for example from shells or shark’s teeth, have often been traded over great distances. Leang Bulu Bettue was then just 60 kilometers (37 miles) from the sea, without difficult terrain between, yet not a single one of the items Brumm found was marine. It shows that by the time these items were made, the people had moved inland and established a culture unique to life in the lowland rainforests, not maintaining any contact with people who lived along the coast.

Instead, the Sulawesians made pendants from bear cuscus bones and beads from babirusa teeth. They also carved geometric patterns on stone flakes. Like so many cultures, they ground ochre for color. There is not a modern human culture that does not involve decorating ourselves, Brumm told IFLScience. It is something no other primate species does, but it is a very ancient part of our evolutionary history, whether done to attract sexual partners or demonstrate rank.

Prehistoric ornaments from Leang Bulu Bettue layers dated to between 30,000 to 22,000 years ago, compared with the species they come from M. Langley and A. Brumm (bear cuscus bone image courtesy of Luke Marsden). Bear cuscus and babirusa photographs: Shutterstock.

Read more: