Death of the dinosaurs. Artist's impression of a pair of giant dinosaurs being startled from their sleep by the blazing fireball of an incoming asteroid or giant meteor. The dinosaurs died out 65 million years ago, along with thousands of other life-forms, at the end of the Cretaceous Period. The theory that the mass extinction was caused by the impact of an extraterrestrial body has recently received support from geological evidence, though numerous other explanations for the death of the dinosaurs have been put forward.
Resurrecting extinct animals is both “exhilarating and terrifying,” says Beth Shapiro, an expert in ancient DNA and a biologist at the University of California, Santa Cruz. Exhilarating because of the unprecedented opportunities to understand life and boost conservation efforts, but terrifying in part for its ethical quandaries.
