Summary: You are what you eat, right? Find out what tuatara eat and how they eat it in the seventh episode of Tuatara.

For my hearing impaired followers, a complete transcript of this podcast follows the show notes on Podbean

Show Notes:

“Tuatara” Royal Ontario Museum, https://collections.rom.on.ca

“Microstructure of dental hard tissues and bone in the Tuatara denture, Sphenodon punctatus,” by J.A. Kierser, T. Tkatchenko, M. C. Dean, M. E. H. Jones, and N. J. Nelson. Front Oral Biol. 2009:13:80-85. https://pubme.ncbi.nlm.nih.gov/19828975

Music written and performed by Katherine Camp

Transcript

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Kiersten - This is Ten Things I Like About…a ten minute, ten episode podcast about unknown or misunderstood wildlife.

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Kiersten - Welcome to Ten Things I Like About… This is a podcast about misunderstood or unknown creatures in nature. Some we’ll find right out side our doors and some are continents away but all are fascinating. 

This podcast will focus ten, ten minute episodes on different animals and their amazing characteristics. Please join me on this extraordinary journey, you won’t regret it.

We have made it to the seventh episode of Tuatara and the seventh thing I like about these super cool reptiles is their diet and dentition. We have hinted a bit about what they eat but today we’ll take a closer look at what that is specifically and how their teeth help. 

Let’s start with food. Tuatara are carnivores. They eat mainly invertebrates like worms and arthropods such as beetles, millipedes, spiders, and weta. Weta are insects native to New Zealand that look similar to crickets but like crickets on steroids. Weta have big bodies, spiny legs, and tusks. They look kind of like a cricket and a warthog had a baby.  

The majority of the tuatara diet is made up of invertebrates but they will also eat lizards, seabird eggs and chicks, and occasionally they venture in to cannibalism and will eat young tuatara. Because of this, juvenile tuatara are active during the day while adult tuatara are active at night. I mean, really, if your relatives might eat you at night, then who wouldn’t want to avoid them. 

Humans that live on the islands where tuatara are found always know when they’ve been hunting because they will see headless birds. Definitely not something you want to come across on a relaxing walk in nature. Why is this the indicator of the tuatara?

The tooth pattern of the tuatara is unique. Just like almost everything else about them. They have two incisor like teeth in front of their top jaw. And they have three rows of teeth (I was not able to find an actual count but am guessing it’s around 85 teeth). One row of teeth lines the bottom jaw and two rows line the top jaw. The bottom row of teeth fit neatly into the two upper rows of teeth when the jaw is closed. Wait for it, we almost have our answer. The jaw motion of the tuatara is also unique. Instead of an up and down motion, like chewing, they have a forward and backward motion, like sawing. 

And there it is! This is why the birds that tuatara hunt are missing heads. They saw them off with their unique teeth. Hah! Didn’t see that coming did you?

Besides the unique pattern of teeth, the structure of their teeth is also unique. They have acrodont teeth which means they are rootless and attached directly to the bone of the jaw. They kind of emerge from the actual bone. This is unlike any other reptile teeth alive today. The teeth are serrated which helps with the sawing motion. Tuatara cannot replace lost or cracked teeth. Once the tooth is gone, it is gone. As tuatara age their teeth wear down from use. They are eating crunchy invertebrates and bony vertebrates, so they do take a beating. Tuatara can live for up to 100 years, so the older tuatara have to switch their diet to softer prey as their teeth wear down. 

Now for a long time, we thought they didn’t have real teeth. We thought they were just bony protrusions that stuck out of the jaw, but some researchers in 2009 looked more closely at the teeth. They looked at teeth from a juvenile as well as an adult and found layers of typical tooth material. This was a surprise.

Using Scanning Electron Microscopy, which is a sophisticated imaging technique that uses an electron beam to examine the surface of various materials, researchers found evidence of enamel containing dentine tubules, dentine, and cementum. All of these are found in other types of teeth. It’s not just serrated, bony material sticky up in their mouths. They have actually teeth. They are different then your average tooth, but they are teeth none-the-less.

These tuatara are just full of surprises!

I hope you enjoyed our dental adventure because my seventh favorite thing about the tuatara is what they eat and how they eat it!

If you're enjoying this podcast please recommend me to friends and family and take a moment to give me a rating on whatever platform your listening. It will help me reach more listeners and give the animals I talk about an even better chance at change. 

Join me next week for another exciting episode about the tuatara.  

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This has been an episode of Ten Things I like About with Kiersten and Company. Original music written and performed by Katherine Camp, piano extraordinaire.