The end-Cretaceous mass extinction 66 million years ago eradicated roughly 75% of the animal and plant species on Earth, including whole groups like non-avian dinosaurs and ammonites. Debate lingers over what caused this extinction, with intense volcanic activity in India’s Deccan Traps and the asteroid strike near the site of the small town of Chicxulub in Mexico the most widely supported hypotheses. Now, a team of researchers from the UK has shown...