Bringing a shark to a knife fight: 7,000-year-old shark-tooth knives discovered in Indonesia

• Excavations on the Indonesian island of Sulawesi have uncovered two unique and deadly artefacts dating back some 7,000 years – tiger shark teeth that were used as blades.
• These finds, reported in the journal Antiquity, are some of the earliest archaeological evidence globally for the use of shark teeth in composite weapons – weapons made with multiple parts.

Our international team used a combination of scientific analysis, experimental reproduction and observations of recent human communities to determine that the two modified shark teeth had once been attached to handles as blades. They were most likely used in ritual or warfare.

7,000-year-old teeth

• The two shark teeth were recovered during excavations as part of a joint Indonesian-Australian archaeological research program.
• The shark teeth are of a similar size and came from tiger sharks (Galeocerda cuvier) that were approximately two metres long.
• Microscopic examination of the teeth found they had once been tightly fixed to a handle using plant-based threads and a glue-like substance.

Examination of the edges of each tooth found they had been used to pierce, cut and scrape flesh and bone. However, far more damage was present than a shark would naturally accrue during feeding. While these residues superficially suggest Toalean people were using shark-tooth knives as everyday cutting implements, ethnographic (observations of recent communities), archaeological and experimental data suggest otherwise.

Why use shark teeth?

• This fact, as well as the fact shark teeth can inflict deep lacerations, probably explains why shark-tooth blades were restricted to weapons for conflict and ritual activities in the present and recent past.
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Shark-tooth blades in recent times

Numerous societies across the globe have integrated shark teeth into their material culture. In particular, peoples living on coastlines (and actively fishing for sharks) are more likely to incorporate greater numbers of teeth into a wider range of tools.

• Observations of present-day communities indicate that, when not used to adorn the human body, shark teeth were almost universally used to create blades for conflict or ritual – including ritualised combat.
• Shark teeth found in Maya and Mexican archaeological contexts are widely thought to have been used for ritualised bloodletting, and shark teeth are known to have been used as tattooing blades in Tonga, Aotearoa New Zealand, and Kiribati.

Other shark tooth archaeological finds

• Indeed, modified shark teeth have been recovered from older contexts.
• A solitary tiger shark tooth with a single perforation from Buang Merabak (New Ireland, Papua New Guinea) is dated to around 39,500–28,000 years ago.
• Our newly described Indonesian shark tooth artefacts, with their combination of modifications and microscopic traces, instead indicate they were not only attached to knives, but very likely linked to ritual or conflict.

• Michelle Langley is an Associate Professor of Archaeology in the Australian Research Centre for Human Evolution at Griffith University, Brisbane.
• Basran Burhan is a PhD student at Australian Research Centre for Human Evolution at Griffith University, Brisbane.