Dinosaurs were already in decline before asteroid impact
DOI: 10.1063/PT.5.029750
Atlantic : Over the 180 million years that dinosaurs ruled Earth, many species came into existence and many died out. Researchers had long assumed that the reason all dinosaurs eventually went extinct was because of a single cataclysmic event—an asteroid that struck the Yucatán Peninsula some 66 million years ago. However, new research shows that dinosaur species may have already been in decline at least 40 million years before the asteroid struck. The researchers attribute the decline to Earth’s changing climate, which had been warm and wet but over time grew cooler. Those climate changes put dinosaurs under considerable stress for a long time, which may have made them more vulnerable when the asteroid struck.
