Komodo dragons (Varanus komodoensis) are the largest extant predatory lizards and their ziphodont (serrated, curved and blade-shaped) teeth make them valuable analogues for studying tooth structure, function and comparing with extinct ziphodont taxa, such as theropod dinosaurs. Like other ziphodont reptiles, V. komodoensis teeth possess only a thin coating of enamel that is nevertheless able to cope with the demands of their puncture–pull feeding. Using advanced chemical and structural imaging, we reveal that V. komodoensis teeth possess a unique adaptation for maintaining their cutting edges: orange, iron-enriched coatings on their tooth serrations and tips. Comparisons with other extant varanids and crocodylians revealed that iron sequestration is probably widespread in reptile enamels but it is most striking in V. komodoensis and closely related ziphodont species, suggesting a crucial role in supporting serrated teeth. Unfortunately, fossilization confounds our ability to consistently detect similar iron coatings in fossil teeth, including those of ziphodont dinosaurs. However, unlike V. komodoensis, some theropods possessed specialized enamel along their tooth serrations, resembling the wavy enamel found in herbivorous hadrosaurid dinosaurs. These discoveries illustrate unexpected and disparate specializations for maintaining ziphodont teeth in predatory reptiles.

科莫多巨蜥（Varanus komodoensis）是现存最大的掠食性蜥蜴，其锯齿状、弯曲和刀片状的牙齿使它们成为研究牙齿结构、功能以及与已灭绝的锯齿类群（如兽脚亚目恐龙）进行比较的宝贵类似物。与其他剑齿虎爬行动物一样，科莫多蜥蜴的牙齿只有一层薄薄的牙釉质，但仍然能够满足刺穿拉食的需求。利用先进的化学和结构成像，我们发现科莫多蜥蜴的牙齿具有独特的适应性来保持其切削刃：牙齿锯齿和尖端上有橙色的富铁涂层。与其他现存的蜥蜴类和鳄鱼类的比较表明，铁固存可能在爬行动物牙釉质中广泛存在，但在科莫多巨蜥和密切相关的剑齿虎物种中最为显着，这表明铁在支撑锯齿状牙齿方面发挥着至关重要的作用。不幸的是，化石化使我们无法持续检测牙齿化石中类似的铁涂层，包括剑齿虎恐龙的牙齿。然而，与科莫多龙不同的是，一些兽脚亚目恐龙的牙齿锯齿上拥有特殊的牙釉质，类似于草食性鸭嘴龙恐龙中发现的波状牙釉质。这些发现说明了掠食性爬行动物在维持剑齿虎牙齿方面的意外和不同的专业化。