World's biggest lizards use iron-coated teeth to tear up prey

The teeth of Komodo dragons, the world’s largest lizards, are coated in a protective layer of iron, a new study has found.

When the nearly-200 pound dragons go after their prey — which can include animals as large as deer or water buffalo — they rip into the unlucky animals’ flesh with serrated teeth, which they use to tear off chunks of skin and muscle that they swallow whole.

The serrated edges and tips of those teeth are wrapped in iron-based enamel, according to findings published on Wednesday in Nature Ecology & Evolution.

Komodos aren’t the only animals to have iron in their teeth. Crocodiles do as well, and so — in trace amounts — do humans.

But the iron in Komodos’ teeth serves an essential purpose of keeping their teeth sharp and continually ready — and there is so much of it that the teeth in a dragon’s mouth are often orange, scientists found.

The researchers described their findings as a means of getting at a more difficult question: whether predatory dinosaurs like tyrannosaurus — which also are thought to have killed prey by ripping it apart with their teeth — also had iron-based teeth.

That’s currently impossible to determine, coauthor Aaron LeBlanc of Kings College London said in a statement.

“We think that the chemical changes which take place during the fossilization process obscure how much iron was present to start with,” he said.

But LeBlanc said that further analysis of the Komodo teeth might identify other compounds in the iron coating “that aren’t changed by fossilization,” which would allow scientists to determine if tyrannosaur teeth were iron coated even after the iron itself is long gone.

The discovery of iron enamel isn’t the first dental surprise that Komodo dragon mouths have offered. It had long been believed that Komodo dragon bites were fatal to prey because serrations provided a home for deadly quantities of blood-poisoning bacteria. 

But in 2009, researchers discovered that they in fact kill with venom.