(Intro)

(0:06) Here's a question for you: If we have no written record to where a species may have been found over time, what sort of evidence can we look for in order to determine where it may have once lived?

I bet weaponry wasn't the first thing that came to mind, but, sure enough, that's exactly what field museum biologists and anthropologists use to collaboratively puzzle out the distribution of central Pacific sharks from more than 100 years ago.

(0:29) Our anthropology collection houses a diverse assortment of pretty impressive weapons created between 1840 and 1898, and later obtained by whalers, missionaries, other museums, and anthropologists from the people of Kiribati.

(0:42) These assorted spears, daggers, and swords — 123 total in our collection — have the unique feature of being studded with shark teeth. Holes are carefully drilled through the base of the tooth and tied to the palm wood with coconut fibers, and occasionally woven in place with human hairs.

(0:57) Shark teeth posses unique identifying markers, meaning we can actually use the size and shape of a tooth in order to determine the species from which it came. This might not be such a big deal if they were only using one type of shark for their weaponry, but marine conservation biologist Joshua Drew was able to determine teeth from eight different species.

And more importantly than that, only six species of those sharks are still found around Kiribati today, meaning that something may have happened 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.

(1:29) What caused the sharks to disappear? Well, maybe they were never a part of the local reef community in the first place. It is possible the people of Kiribati were trading with nearby islands, travelers, or whalers in order to obtain teeth from the dusky or spot-tail sharks.

But it's also possible that overfishing could be a cause as to why these two sharks have not been counted in modern ichthyological surveys, as could fluctuating ocean temperatures due to changes in global climate.

While we may not be able to determine what caused the sharks to leave, this study serves as an important reminder of how museum collections can serve unpredictable purposes, and provide insights to questions we hadn't previously thought to ask.

(2:12) So, how does one protect themself against shark tooth weaponry? Well, you want to use the resources that are abundant and available to you, and they made armor out of coconut fibers and human hair, and then would wear the blowfish as an armored helmet.

There's also a lot of really interesting variety in these weapons. Like, they don't always follow one kind of cookie cutter pattern, or in any kind of make or model way; you have ones that are single shafts, and they have multiple rows of teeth on them; ones that are two-pronged; this one is four-pronged; one only has one tooth on it. Some are 25 feet tall... I don't know how you would fight with something like that.

Camera man: How would you fight with something like that?

Emily: How would I fight with something like that? I would just show up to battle with it, and I have a feeling the other people would probably back off. 

[End Credits]