Sharp-toothed Messer - The Komodo dragon's teeth are coated with iron
With the discovery of British scientists, the expression "razor-sharp teeth" takes on a whole new meaning. It seems that iron teeth are more of an idea from comic book authors than an evolutionary strategy. However, they have been found nonetheless. Currently in Komodowaranas.
Scientists from King's College London have shown that iron is concentrated along the edges and tips of Komodowaranas' teeth. According to the study that appeared in the journal "Nature Ecology & Evolution" on a Wednesday, this observation by researchers could also provide clues as to how, for example, the T-Rex may have butchered its prey.
Did the T-Rex have iron on its teeth?
The Komodowaranas, which are native to Indonesia, are the largest living variety of monitor lizard, with an average weight of about 80 kilograms. As deadly predators, they eat almost every type of flesh, from smaller reptiles and birds to deer, horses, or water buffalos. Humans are attacked by them from time to time. "Komodowaranas have curved, serrated teeth, with which they tear apart their prey, just like the flesh-eating Dinosaurians. We want to use this similarity to find out how carnivorous dinosaurs could have fed themselves and if they used iron in their teeth in the same way as the Komodowaran", says Aaron LeBlanc, a lecturer in dental biology at King's College London and the main author of the study.
To understand the chemical and structural composition of Komodowaranas' teeth, researchers searched museums for Komodowaran skulls and teeth and analyzed the teeth of Ganas, a 15-year-old Komodowaran that lived in the ZSL Conservation Zoo in the London Zoo, using imaging techniques and chemical analyses. With their help, they were able to analyze the protective layer of iron oxide on the tooth edges and tips.
Researchers have not been able to determine the chemical and structural composition of dinosaur teeth yet. "Unfortunately, with the technology we have available, we cannot determine whether fossilized dinosaur teeth had a high iron content or not. We believe that the chemical changes that occur during the fossilization process obscure the original iron content", says LeBlanc.
With further analyses of Komodo teeth, they might be able to find other markers in the iron coating that do not change during fossilization. "With such markers, we would certainly know whether dinosaurs had iron-coated teeth, and we could better understand these wild predators", the researcher believes.
Surprisingly thin enamel on the teeth of meat-eating dinosaurs
Thomas Tütken, a paleontologist at Johannes Gutenberg University Mainz, also believes this is possible. "For our chemical analyses of dinosaur teeth, we use, among other things, laser ablation", says Tütken. By shooting a laser at a dinosaur tooth, one can determine the concentration of individual elements that make up the tooth enamel, as well as their spatial distribution.
One expert finds it not implausible that one encounters iron during this process. "When considering dinosaur tooth enamel, it is important to note that additional iron deposits can also occur during tooth fossilization after death," says Tütken. "However, we know that flesh-eating dinosaurs have a much thinner layer of hard tooth enamel than herbivores." This may seem illogical at first, as a carnivorous dinosaur like a T-Rex, which also crushes bones, would be reliant on sharp and stable teeth. However, factors other than the sharpness and hardness of the teeth also play a role, such as the internal structure of the tooth crown made of enamel: "The spatial arrangement and size of tooth enamel crystals determine how stable the tooth enamel is," says Tütken.
Not only Komodowarans have iron-hard teeth
However, the mineralization grade of tooth enamel and the type of biominerals in tooth enamel, which typically consists of about 96% of the calcium phosphate mineral hydroxyapatite, also play a role. The incorporation of additional substances such as iron oxides during tooth formation could have led to increased strength and wear resistance.
This is supported by the fact that not only Komodowarans have iron-hard teeth. For example, a yellow-orange luminescent iron oxide compound coats the cutting edges of a beaver's incisors. And certain mouse species have red-colored teeth due to iron compounds. "The harder iron oxide-containing tooth enamel layer of rodent incisors leads to an automatic sharpening of the cutting edges of the teeth," says Tütken. "Humans have taken note of this in the context of bionics from nature and use the principle for the construction of self-sharpening knives and tools." Whether dinosaurs also benefited from this is still to be determined.
The study on Komodowaranas' teeth suggests that Tyrannosaurus Rex might have also utilized iron in its teeth for butchering prey, as observed in the Komodowaranas' serrated teeth. Interestingly, not just Komodowarans have iron-hard teeth; mammals like beavers and certain mouse species also have teeth with iron compounds, contributing to their wear resistance and self-sharpening.
