66 million years ago, the last dinosaurs vanished from Earth. We're still trying to understand why. New fossils of abelisaurs—distant relatives of the tyrannosaurs—from north Africa suggest that African dinosaurs remained diverse up to the very end. And that suggests their demise came suddenly, with the impact of a giant asteroid.

66 million years ago, the last dinosaurs vanished from Earth. We’re still trying to understand why. New fossils of abelisaurs—distant relatives of the tyrannosaurs—from north Africa suggest that African dinosaurs remained diverse up to the very end. And that suggests their demise came suddenly, with the impact of a giant asteroid.

The causes of the mass extinction have been debated for two centuries. Georges Cuvier, the father of paleontology, thought extinction was driven by catastrophes. Charles Darwin thought gradual changes in the environment and competition between species slowly drove lineages extinct.