Rise of the mammals began before dinosaur extinction, research suggests

Study of prehistoric mammal teeth reveals variety of shapes, helping to overturn theory that diversity was kept in check by dominance of dinosaurs

Mammals experienced a boom in diversity long before the dinosaurs became extinct 66 million years ago, overturning the notion that their evolution was curbed by the success of the land-based reptiles, scientists have said.

It has long been thought that dinosaurs kept diversity among mammals in check by dominating food and resources, with early mammals thought to be limited to small, insect-eating creatures. But recent fossil finds have called the idea into question, suggesting that they had a wider range of shapes and sizes than previously thought.