The Lull after the Dinosaurs

It was generally believed in paleontology that, once the dinosaurs vanished, the mammals blossomed quickly into new niches and new species, some of which gave rise to the mammals of today. A new study, though, shows that didn't happen. Instead, the new mammals were generally evolutionary dead ends. The little critters that were the original mammalian ancestors soldiered on for 10-15 million years before branching into the mammalian family trees that survive to the present day.