Shark species that existed for less than four million years die out more frequently than older ones. This is the result of a new study by the University of Zurich. "Understanding the mechanisms of extinction, including the characteristics that make certain species more vulnerable than others, is crucial in a changing world," the researchers wrote in the study published on Wednesday in the scientific journal Proceedings B. +Get the most important news from Switzerland in your inbox The researchers analysed 20,000 fossils of sharks and rays from the last 145 million years. They discovered a clear pattern: younger species that have only existed for a few million years are more susceptible to extinction than older species that have survived for much longer. Mass extinction During their investigation, the researchers also discovered evidence of previously unknown mass extinctions. While the sharp reduction in shark and ray species during the first mass extinction of the dinosaurs around ...