Komodo Dragons Have Teeth of Iron

As though Komodo dragons were not remarkable enough already, these enormous lizards quite literally possess iron teeth.

A fresh study of these fearsome predators’ teeth has identified concentrated iron deposits along the serrated tearing edges and at the tooth tips. The deposits help keep the teeth exceptionally sharp as the animals strip flesh from the prey they consume.

Although iron reinforcement occurs in the teeth of many vertebrates, Komodo dragons (Varanus komodoensis) and other species with serrated teeth, known as ziphodonts, are the most dramatic examples identified so far.

Indeed, the iron concentration along the cutting edges of Komodo dragon teeth is so high that it gives them an orange hue.

Iron teeth give Komodo dragons a sharp edge

Iron has never previously been discovered so specifically concentrated on the cutting edge of a vertebrate tooth. The finding indicates that a tougher cutting edge offers a competitive benefit, while potentially shedding light on how some of the most formidable dinosaurs consumed their food.

"Komodo dragons have curved, serrated teeth to rip and tear their prey just like those of meat-eating dinosaurs," says palaeontologist Aaron LeBlanc of King's College London.

"We want to use this similarity to learn more about how carnivorous dinosaurs might have ate [sic] and if they used iron in their teeth the same way as the Komodo dragon."

Komodo dragons are, to put it plainly, extraordinary animals.

They are not only the largest living lizard species - the biggest specimen ever measured weighed 166 kilograms, although most are roughly half that mass - but they are also powerful, quick and cunning. They can overcome prey far larger than themselves, and beneath their scaly skin they wear armour made of bone across their bodies.

They are certainly accomplished hunters. Their formidable jaws can inflict a vicious bite containing anticoagulant venom, which increases the rate at which their prey loses blood.

Their exceptionally sharp, serrated teeth, which curve like scimitars, are also well known.

What Komodo dragon teeth reveal about dinosaurs

Because Komodo dragons are the largest living lizards, and because comparable ziphodont teeth have been recorded in extinct dinosaurs such as the theropod group that includes Tyrannosaurus rex, scientists believe these remarkable lizards’ dentition may offer clues to how dinosaurs bit, tore and fed.

To investigate the effectiveness of Komodo dragon teeth more closely, researchers examined those of Ganas, a male Komodo dragon that lived at London Zoo. He was euthanised in February 2023 after receiving a diagnosis of degenerative arthritis that could not be treated.

Ganas’ remains were preserved, allowing the team to carry out a detailed investigation of his teeth.

Using sophisticated microscopy and spectroscopy, the researchers analysed the composition of Ganas’ teeth. They established that the orange colouring on the serrated edges and tips results from iron being sequestered in those areas.

This points to the possibility that dinosaurs had a comparable adaptation. However, when the scientists examined dinosaur teeth, they could not establish whether that was true.

"Unfortunately, using the technology we have at the moment, we can't see whether fossilized dinosaur teeth had high levels of iron or not. We think that the chemical changes which take place during the fossilization process obscure how much iron was present to start with," LeBlanc explains.

"What we did find, though, was that larger meat-eating dinosaurs, like tyrannosaurs, did change the structure of the enamel itself on the cutting edges of their teeth. So, while Komodo dragons have altered the chemistry of their teeth, some dinosaurs altered the structure of their dental enamel to maintain a sharp cutting edge."

Protecting endangered Komodo dragons

The team hopes that a more comprehensive study of Komodo dragon teeth will uncover features linked to their iron-reinforced serrated edges that fossilisation would not have removed. Such evidence could improve our understanding of how these ancient animals lived.

Naturally, the results also reveal more about Komodo dragons themselves - living, breathing creatures that still inhabit our planet.

"Komodo dragons are sadly endangered," says herpetologist Benjamin Tapley of the Zoological Society of London, "so in addition to strengthening our understanding of how iconic dinosaurs might have lived, this discovery also helps us build a deeper understanding of these amazing reptiles as we work to protect them."

The research was published in Nature Ecology & Evolution.