Scientists have debated whether the dinosaurs were already in decline before a massive asteroid impact finished them off 66 million years ago. New research shows they were thriving in their final days. Help EarthSky keep going! Please donate what you can to our annual crowd-funding campaign.Dinosaurs once reigned on Earth, until a cataclysmic event – now thought to have been a massive asteroid impact, or possibly intense volcanic activity – wiped them out about 66 million years ago during the Maastrichtian age at the end the Late Cretaceous epoch. This mass extinction event was sudden and brutal, powerful enough to...