I recently read an article on how the teeth of the Komodo dragon, Varanus komodoensis, are similar to those of theropod dinosaurs. Okay, that’s interesting, but what is unique about the teeth of theropod dinosaurs? What are the pertinent characteristics?
Komodo dragons are the largest living lizard, a reptile, but not a descendant of dinosaurs. I’ve had the pleasure of meeting them in person on the islands of Komodo and Rinca. One of my bucket list trips is renting a bed on Rinca and spending a week with these fabulous reptiles. However, that’s not allowed, sigh. People often think they are at the top of the food chain, but the unique Komodo Dragon is at the top on these islands. Their primary predator is another Komodo dragon. One of my favorite memories of visiting Rinca was watching a couple of tourists take selfies with a giant male dragon. They leaned down close to his head. I had my camera filming just in case the dragon decided to enjoy a quick tourist snack, but the dragon looked at me with a twinkle in his eye as if to say no, that would be too easy!
Komodo dragons and the theropod dinosaurs are called apex predators. An interesting behavior of both groups is the way they frequently shed their teeth. Not just an occasional, got-it-caught-on-a-prey’s bone-type tooth loss, but regular shedding. Dragons kept in captivity litter the ground of their enclosure with teeth. A dragon has up to five replacement teeth per tooth positioned in their jaws. This many back-up teeth are unique among predatory reptiles; others only have two replacement teeth in their jaws.
Dragons have a rapid replacement rate of every forty days! Even theropods took up to three months for tooth replacement. Interestingly, the dragons’ teeth changed with their behavior. Young dragons, who spend a lot of time in trees out of the way of the adults, have delicate teeth used for eating insects and small vertebrates. As they become adults, they descend from the trees to hunt larger prey on the ground.
When examined closely, the dragon teeth were very similar to those of the theropod dinosaur: recurved teeth with serrated cutting edges, strengthened by dentine cores. Teeth like these are called ziphodont. Theropods had ziphodont teeth. The ziphodont tooth structure seems useful for many eating activities: killing, cutting, and crushing bones. Different forces could be applied as needed. The living lizards provide an exciting opportunity to see ziphodont teeth in action.
In addition, the front teeth of the adult dragons are small or missing, allowing for tongue-flicking, so they can detect prey without opening their mouths – such a waste of unnecessary energy!
Since dragons are not direct descendants of dinosaurs, the development of these teeth is an example of convergent evolution. Were their hunting and consumption behaviors comparable along with similar teeth? This is an excellent opportunity to compare ancient and modern predatory reptiles.
Visiting wild Komodo dragons was a highlight of my life. I like large lizards, and seeing the largest was an apex event!
If you are as interested in Komodo dragons as I am, you may enjoy my downloadable workbook, which is all about iguanas.
Learn more: Tea Maho et al., Exceptionally rapid tooth development and ontogenetic changes in the feeding apparatus of the Komodo dragon, PLOS ONE (2024). DOI: 10.1371/journal.pone.0295002
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