That’s the “tooth” of it

Over here at Wieland Wildlife Home, we have been working closely with our Education Team to provide some great virtual programs to school kids of all ages (we have programming for students in grades pre-K through high school)! Each program has a different theme, and we are able to present an ambassador animal that fits into the theme we discuss, as well as make sure there is time at the end of each program for the students to ask questions. Because we love being able to answer questions! Depending on the age of the group, questions can range from asking about the specific species they meet, more in-depth questions about the theme, more details on something we only briefly discussed that may not have been related to the species or theme, or sometimes the kids just want to tell us the corn snake is the same color as their favorite snack, Takis!

Last week, I did a program for a group of second graders discussing how and why animals make sounds, and the animal I brought with me was our 30-year-old ball python, Nyoka. In talking about the different body parts and organs snakes use, or don’t use, to make sounds compared to humans (lungs, lips, tongue, teeth, etc.), one student was prompted to ask me at the end of the program, “Why are its teeth like that?” That got me smiling and thinking quickly to answer his question live on the program, but as I walked back to Wieland after the program, I kept thinking about the “why are teeth shaped that way” question about all the animals I work with in Wieland. And let me tell you, that’s a lot of teeth to think about! I’m not kidding, it’s hundreds of teeth.

As humans, it is so easy to understand the “why.” Incisors for tearing, canines for grabbing and tearing, molars for mashing. It also allows us to understand why humans are natural omnivores. Various shaped teeth allow us to eat a variety of foods, even without the need for man-made utensils! But what about that snake I brought with me? What about the rabbit or tenrec or prehensile-tailed skink? Why ARE teeth like that?! It’s questions like these that, on the surface, seem simple enough for us to answer, but when you really think about the animal and its natural history is when the gears turn, and you can truly answer the Why!

So why are snakes’ teeth that way? Well, first we need to know what snakes’ teeth look like. Snakes have some pretty awesome teeth! Depending on the species, snakes can have up to 110 teeth in their mouths. These teeth are similar in shape to needles: long, thin, sometimes hollow to allow for venom transfer. But all these teeth face backwards, which is very important. This is what the student wanted to know when he asked his question. Well, snakes don’t have limbs to hold onto food, just a mouth, and a long body. Since they are grabbing live prey with only a mouth, that mouth needs to be equipped with the right tools to hold onto prey, so the prey doesn’t escape while the rest of the body either constricts, squishes, or holds on while venom kicks in. So having needle-like, rear facing teeth allows the snake to grab and hold and never let go.  

Okay, so now that we’ve agreed sharp teeth are very important, let’s talk about some other sharp teeth! I’ve talked in previous stories about these cute little mammals called lesser Madagascar hedgehog tenrecs. They are about the size of your palm and covered in small keratin spines all over their backs. They are an omnivorous species that consume a large amount of insects, but because of their small size, they are easy prey for larger animals. So how do their teeth help them with eating as well as predator defense? I’m so glad you asked! Compared to their small size, they have fairly long canine teeth. These canines are long enough to see sticking out from under their lips, even when they are resting peacefully waiting for care staff to bring them dinner. All their teeth are small, but very sharp. This is great because that means they can catch crawling invertebrates quickly and devour them even more quickly! Sharp teeth and strong jaws allow the tenrec to consume plant material that most humans would need a fork and knife to slice through.

Now, back to those impressive canine teeth. When a tenrec feels threatened by a predator, they will hiss and wiggle their noses up and down. By doing this, they are showing off those impressively long canine teeth, and hoping this display will ward off predators. If that doesn’t work, they will charge toward the predator and eventually bite the predator to scare it off!

Let’s talk more sharp teeth, shall we? Specifically, the prehensile-tailed skink. Skinks as a group have small, cone-shaped teeth. Again, they are very small teeth, especially compared to the size of their heads, but they are sharp nonetheless! But what makes the prehensile-tailed skink so interesting is that, in a group of skinks that are largely carnivorous and omnivorous, these guys are completely herbivorous. They only eat plants! So why would the prehensile-tailed skink still need these same sharp conical teeth? PLANTS! Prehensile-tailed skinks are native to the Solomon Islands in the South Pacific. There, they consume various leaves, fruits, and flowers, and since there are no care teams in the wild to chop their plants and fruits up, they need to be able to do that on their own. That’s why having the cone-shaped teeth is so useful! Thanks to these very sharp teeth, and very powerful jaws, the prehensile-tailed skink is able to bite small pieces of these plants off at a time, to make eating a large plant so much easier.

Let’s circle back again to mammals and the variety of teeth we have in our own mouths. Humans have four different types of teeth in our mouths: incisors, canines, premolars, and molars. Again, this is great for an omnivorous diet, but what if you’re not an omnivore? What if you are a rabbit? Great question! Rabbits are part of a taxon called Lagomorphs, which also include pikas and hares. They are not the same as rodents for a few reasons, but one in particular are those teeth! We understand that rodents have one set of incisors in their top and bottom jaws that grow continuously (also known as hypselodont) but what makes lagomorphs different is behind their top set of incisors, is a secondary, smaller peg-like set immediately behind the front incisors. With lagomorphs having hypselodont teeth, they need to consume food that will wear their teeth down. This is really cool to think about: lagomorphs need their incisors to cut the grasses, leaves, shrubs, and bark for eating and at the same time need to eat bark and tough plants to file down those ever-growing incisors! None of the other animals I have talked about or work with at Wieland use their teeth to eat and at the same time use their food to keep their teeth from growing too long. Lagomorphs also do not have canines or separate premolars and molars. Being herbivores, they have no use for canine teeth. In place of canines is a diastema, or just an empty space along the jaw, and they have what are called “cheek teeth,” since there is no separation of premolars to molars. And just like with other species with molars, or in this case the cheek teeth, these help with grinding up the tough plant material they consume.

So thanks very much to the young student who asked me about snake teeth last week! As you can see, I had fun thinking about all the different types of teeth I get to see on my animals each day, and understanding even more how and why these teeth are so important!

(photo: Emily B.)

Emily B.
Keeper II, Ambassador Animals