Researchers from Field Museum of Natural History led by Columbia University's Joshua Drew discovered two new species of sharks that had not been reported in historic or contemporary records after analyzing weapons made of shark teeth in the Gilbert Island reefs in Central Pacific, a new study published in the journal PLOS ONE reveals.
Sharks were culturally important to the Gilbertese Islanders; historic records indicate a complex ritual system surrounding shark fishing and making fishing gear and weapons from shark teeth. For the current study, the researchers analyzed a collection of 120 of these weapons from the Field Museum of Natural History, including some that resemble clubs, daggers, lances, spears and swords. They identified eight species of sharks based on the teeth used in these weapons, two of which have never been reported from these waters, in either historical surveys or contemporary analysis. Both these species are currently common in other areas, so while it is possible that these species may still be living undiscovered in the GIlberts, it is more likely that the local populations have been driven to extinction.