Have you ever wondered how scientists can figure out where a species used to live if there are no written records? Surprisingly, one of the clues comes from ancient weaponry. At the Field Museum, biologists and anthropologists have been using this unique approach to trace the historical distribution of sharks in the Central Pacific, dating back over a century.
The museum’s anthropology collection includes an intriguing array of weapons crafted between 1840 and 1898. These weapons, obtained by whalers, missionaries, and collectors from the people of Kiribati, consist of spears, daggers, and swords—123 in total—adorned with shark teeth. The teeth are meticulously drilled and tied to palm wood using coconut fibers, sometimes even woven with human hair.
Shark teeth are unique, with distinct markers that allow scientists to identify the species they came from based on their size and shape. Marine conservation biologist Joshua Drew discovered teeth from eight different shark species in these weapons. Interestingly, only six of these species are currently found around Kiribati. This suggests that the spot-tail shark and the dusky shark, the two ‘missing’ species, might have disappeared from the region between the late 19th century and today.
Several theories could explain the absence of these sharks. It’s possible they were never part of the local reef community, and the people of Kiribati might have traded with nearby islands or whalers to acquire the teeth. Alternatively, overfishing and climate change, which affects ocean temperatures, could have led to their disappearance. Although the exact cause remains uncertain, this study underscores the unexpected ways museum collections can provide insights into historical ecological changes.
Faced with the threat of shark-tooth weaponry, the people of Kiribati ingeniously used available resources for protection. They crafted armor from coconut fibers and human hair and even fashioned helmets from blowfish. The variety in these weapons is remarkable; they range from single-shaft designs with multiple rows of teeth to two-pronged or even four-pronged versions. Some weapons are impressively large, reaching up to 25 feet tall! It’s fascinating to imagine how these formidable tools were used in battle, likely intimidating any opponent.
This exploration of ancient weaponry not only reveals the historical distribution of shark species but also highlights the innovative ways humans have adapted to their environments. By examining these artifacts, we gain a deeper understanding of both ecological history and human ingenuity.
Engage in a hands-on workshop where you will examine replicas of shark teeth and learn to identify different species based on their unique markers. This activity will enhance your understanding of how scientists use physical evidence to trace historical species distribution.
Create an interactive map that traces the historical and current distribution of the eight shark species identified in the article. Use digital tools to visualize changes over time and discuss potential reasons for these shifts with your peers.
Participate in a structured debate where you will explore various theories explaining the disappearance of certain shark species from Kiribati. Research and present arguments for overfishing, climate change, and trade as potential causes.
Using craft materials, design and build a model of a shark-tooth weapon. Focus on the engineering and cultural aspects of the design, and present your creation to the class, explaining its historical significance and potential use in battle.
Take a virtual tour of the Field Museum’s anthropology collection, focusing on the shark-tooth weapons. Reflect on how these artifacts provide insights into ecological and cultural history, and write a short essay on your findings.
Here’s a question for you: if we have no written record of where a species may have been found over time, what sort of evidence can we look for to determine where it may have once lived? You might not think of “weaponry” as the first clue, but that’s exactly what Field Museum biologists and anthropologists use to piece together the distribution of Central Pacific sharks from over 100 years ago.
Our anthropology collection includes a diverse assortment of impressive weapons created between 1840 and 1898, later obtained by whalers, missionaries, and other collectors from the people of Kiribati. These assorted spears, daggers, and swords—123 in total—feature a unique design: they are studded with shark teeth. Holes are carefully drilled through the base of the tooth and tied to the palm wood with coconut fibers, sometimes woven in place with human hair.
Shark teeth have unique identifying markers, allowing us to determine the species from which they came based on their size and shape. This is significant because marine conservation biologist Joshua Drew identified teeth from eight different species. Notably, only six of those species are still found around Kiribati today, suggesting that something may have changed between the end of the 19th century and today that affected the distribution of the spot-tail shark and the dusky shark, the two ‘missing’ species.
What caused the sharks to disappear? It’s possible they were never part of the local reef community. The people of Kiribati may have been trading with nearby islands or whalers to obtain teeth from the dusky or spot-tail sharks. Overfishing and fluctuating ocean temperatures due to climate change could also explain why these two sharks are absent from modern surveys.
While we may not pinpoint the exact cause of their disappearance, this study highlights how museum collections can serve unexpected purposes and provide insights into questions we hadn’t previously considered.
So, how does one protect themselves against shark-tooth weaponry? Utilizing available resources is key. They crafted armor from coconut fibers and human hair and even used blowfish as helmets. There’s a fascinating variety in these weapons; they don’t all follow a single pattern. Some have single shafts with multiple rows of teeth, while others are two-pronged or even four-pronged. Some are quite large—up to 25 feet tall! It’s hard to imagine how one would fight with such a weapon. I can only imagine showing up to battle with it and having the other side back off!
Sharks – Cartilaginous fish known for their predatory skills and significant role in marine ecosystems. – Marine biologists study sharks to understand their impact on oceanic food chains and biodiversity.
Anthropology – The scientific study of humans, human behavior, and societies in the past and present. – Anthropology provides insights into the cultural practices and social structures of ancient civilizations.
Biologists – Scientists who study living organisms and their interactions with the environment. – Biologists are conducting research on the genetic diversity of coral reefs to aid in their conservation.
Species – A group of organisms that can interbreed and produce fertile offspring. – The discovery of a new species of primate in the Amazon rainforest has excited the scientific community.
Weapons – Tools or instruments used by humans or animals for defense or hunting. – In anthropology, the study of ancient weapons helps us understand the technological advancements of early human societies.
Kiribati – An island nation in the central Pacific Ocean, known for its unique cultural heritage and environmental challenges. – Researchers are examining the impact of rising sea levels on the ecosystems and communities of Kiribati.
Conservation – The protection and preservation of natural resources and environments. – Conservation efforts are crucial for maintaining biodiversity and preventing the extinction of endangered species.
Climate – The long-term patterns of temperature, humidity, wind, etc., in an area. – Climate change is a significant focus of ecological studies due to its impact on habitats and species distribution.
Ecological – Relating to the interactions between organisms and their environment. – Ecological research is essential for understanding how human activities affect natural ecosystems.
History – The study of past events, particularly in human affairs. – The history of human migration patterns is a key area of research in anthropology.
