Scientists have discovered that the serrated edges of Komodo dragons’ teeth are tipped with iron.

Led by researchers from King’s College London, the study gives new insight into how Komodo dragons keep their teeth razor-sharp and may provide clues to how dinosaurs like Tyrannosaurus rex killed and ate their prey.

Native to Indonesia, Komodo dragons are the largest living species of monitor lizard, averaging around 80kg. Deadly predators, Komodos have sharp, curved teeth similar to many carnivorous dinosaurs. They eat almost any kind of meat, from smaller reptiles and birds to deer, horses, or water buffalo, pulling and tearing at their prey to rip flesh apart.

The researchers discovered that many reptiles have some iron in their teeth, but Komodo dragons have concentrated the iron along the cutting edges and tips of their teeth, staining them orange. Crocodiles and other monitor lizards, by comparison, have so little that the iron is often invisible.

Through advanced imaging and chemical analysis, the team was able to observe that the iron in Komodo dragons’ enamel is concentrated into a thin coating on top of their tooth serrations and tips. This protective layer keeps the serrated edges of their teeth sharp and ready to be used at a moment’s notice.

The research, published on July 24 in Nature Ecology & Evolution, leads to new questions and avenues for research into how extinct species such as dinosaurs lived and ate.

“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 that take place during the fossilization process obscure how much iron was present to start with.

“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.

“With further analysis of the Komodo teeth, we may be able to find other markers in the iron coating that aren’t changed during fossilization. With markers like that, we would know with certainty whether dinosaurs also had iron-coated teeth and have a greater understanding of these ferocious predators.”