More than 30 years ago, researchers discovered vertebrae, ribs and a tooth in the High Alps of eastern Switzerland. The typical shape indicated that they had to originate from large marine reptiles known as ichthyosaurs, but there was a lack of corresponding comparative material. A new study has now allowed a more precise classification. According to the findings, they belong to three different ichthyosaurs of around 15 to around 20 meters in length. The tooth is particularly unusual: With a root diameter of six centimeters, it is twice as large as the largest aquatic dinosaur tooth found to date.