Dinosaurs weren't in decline when an asteroid smashed into Earth and wiped them out, scientists say. Instead, the idea that dinosaur diversity was declining before the asteroid struck 66 million years ago is likely based on faulty fossil data, according to a study that looked at nearly 18 million years of fossil evidence.
Fossil discoveries have long indicated that dinosaurs were shrinking in numbers and diversity prior to the asteroid impact at the end of the Cretaceous period. Previously, some researchers believed this was a sign that dinosaurs were already on the road toward extinction even before the cataclysmic encounter with a space rock. However, this idea has long been controversial, with other researchers arguing that dinosaur diversity was doing just fine at the time of their demise.
